Indri, Chekov and even Reichard laughed uproariously. Oddly, Kirk smiled without laughter, a far away, pensive look on his face.

"What’s the matter, Cap’n?" Reichard asked, somewhat puzzled. "Miss the point?"

Kirk shook his head. "No, Ken, I got the joke. It was just one I’ve heard before, slightly differently, and it made me think a little about humor in general, and how a lot of it seems pretty nearly universal across time and space."

"Aww, who beat me to the punch?" Reichard was clearly disappointed that what he thought was a fresh bit of humor was anything but.

"Believe it or not, Giacomo Eletto, only he told it of a cave man, and a saber-toothed tiger entering the cave man’s mother-in-law’s cave. When his wife runs in and tells him he has to do something about the saber-toothed tiger in her mother’s cave, the cave man says, ‘Why? What do I care what happens to a saber-toothed tiger?’ It’s the same joke, really, just the version from a couple of hundred years ago. And Giac said his grandpa had heard it from his grandpa."

"You mean that Human icicle from the twenty-first century we thawed out on the way to Kahla? Man, I bet his grandpa’s grandpa was the cave man that said it!" Reichard got a round of laughter from everyone with that.

"Good one, Ken. Getting back to my point, Giac and I started swapping jokes one evening, over and after dinner, before we left Kahla. What amazed me was how many of the jokes I knew, he’d heard, and how many of his jokes, I’d heard. The details differed—different people or species being the targets—but otherwise almost identical. It might amaze you to know that he even had a couple I’d never heard." Kirk shook his head. "Maybe it would amaze you more to know that I even got ‘em when he told ‘em."

"You have my curiosity piqued, Captain," Indri interjected. "Do you recall any joke he told that you’d never heard?"

"Hmmm…" Kirk scratched his head for a moment. "Okay, here’s a modernized version of one of his jokes. Know how many times a Vulcan laughs at a joke?"

The other three stared at each other for a few moments. "Nyet, Kyptin," Chekov finally confessed. "How many times?"

"Three. Once, when it’s told; once when it’s explained; and then the third time, months later, when he finally understands it." There was a chorus of snickers. "Now, a Romulan only laughs twice. Romulans never really get it." The snickers turned into laughter. "Klingons only laugh once: no one in their right mind would risk their lives explaining a joke to a Klingon." The three men began shaking with laughter. "And Starfleet brass never laughs at all: they’ve already heard it."

Indri, Chekov and Reichard hooted with laughter, tears running down their faces. Kirk waited for them to settle down a little bit, then continued. "What I was thinking about, when Ken accused me of missing the punch line, was how little the grand sweep of humor, among other things, had changed in that length of time. Eletto told the joke about a Frenchman, a German, an Englishman and a New Yorker, but it’s otherwise the same. I guess it says something about how little we’ve really changed, no matter how much our technology and society have changed around us. I’d bet if we could make our way back to, say, the Assyrian Empire or Ancient Egypt, we’d find that the jokes were pretty much the same then, too."

"I do not know about jokes from that far back, Captain, but from what one of my teachers once told me, the oldest known graffiti, properly translated, would not stand out as unusual on modern lavatory walls," Indri added. "Indeed, I have found that many of the jokes told by Tellarites, Andorians and even Klingons, are not much different from those told by Humans, and other than puns, are mutually understood. I suppose that if Vulcans and Romulans told jokes, the same would be true of them. The graffiti is also strikingly similar across cultures. But speaking of Doctor Eletto, Captain, have you heard from him lately? I have more or less lost track of him since I left the Enterprise."

"Heard from him? Yes! For a while, I’d get little notes, you know the kind of thing: local news, just letting us all know he was alive, well, and getting along adequately, sort of like the newsletter that people put in Christmas or Chanukah or Kwanzaa cards. But Bones got the most recent note from him." Kirk shook his head. "Only five words long, but you wouldn’t believe the trouble it started."

"Try us, Cap’n," Reichard suggested. "After what we’ve all been through, you might be surprised what we can believe."

McCoy and M’Benga were toiling over the prostrate form of an injured Engineering cadet, collaborating in re-attaching an amputated foot. From the wall communicator, Uhura’s voice interrupted their concentration.

"Doctor McCoy, I have received a message for you; it’s marked urgent."

"Well, pipe it through, Uhura," McCoy responded, a hint of annoyance in his voice. "I’m in the middle of procedure here, and I can’t come to the bridge."

"It was transmitted as text, Doctor," Uhura responded calmly. "Do I have your permission to open it and read it to you?"

Slightly embarrassed, McCoy said, "Sorry, Uhura. If it’s text, it must be trouble; you better read it to me. What’s it say?"

There was a momentary pause. "It reads, ‘Need help. Come quickly. Grandpa.’ That’s all."

M’Benga looked his colleague in the eye. "If that’s from who I think it’s from, Leonard, we are in hard vacuum at warp speed without an environmental suit."

"Ben, there’s only one being in all the Federation that would sign a letter to me with the name ‘Grandpa,’ and we both know it: Giac Eletto. And if he’s yelling for help, you’re dead right: we are in big trouble."

Uhura broke into the dialogue. "Doctor, under the circumstances, I think I need to share this with the captain. Request permission..."

"Just let me check on Jim’s last physical, Uhura; I want to be sure that his heart’s up to the fright."

Before Uhura could answer, Kirk’s voice came over the communicator. "I appreciate your concern, Bones, but don’t waste your time. We’ve just received a distress call with a personal request for assistance from del Anders. We’re on our way to Gamma Virginis, as fast as Scotty will let me push the Enterprise."

*****

McCoy, Kirk and Spock materialized on the Jovian Platform. "I still don’t see why they insisted we come here, Jim," McCoy complained. "I mean, it’s real nice the way they’ve spiffed this place up and all, but I thought that the problem was on the planet, not on this contraption."

"Indeed, Doctor McCoy," Spock responded. "But I have no doubt that there is an eminently logical reason why we were brought here. Furthermore, I appreciate the opportunity to see what has been achieved. The transformation has been quite impressive. It could easily be mistaken for a park, or a well-tended ecological refuge on Earth."

From behind the men, Eletto’s voice rang out. "Welcome back, gentlebeings, and thank you for the praise of our efforts to put the Jove back to rights. And you’re quite right, Leonard, the problem is on the surface, which is exactly why the three of you were brought here."

The three men turned toward the voice. Sitting under an immense oak tree, his back to the trunk, was Giacomo Eletto.

"How did you get that oak to grow so fast?" Kirk sputtered in surprise. "It looks like it’s a couple hundred years old or more."

"Oh, it’s got to be every bit of three hundred years old, Captain," Eletto smiled. "In the interests of properly restoring the Jovian Platform’s intended ecology, the Eletto Foundation was kind enough to locate the tree and bring it here. It’s a genetic match to the seedling we planted, on the platform. I planted it in my back yard, a couple of years before we planted the one on the Jove. The nursery took the grafted material from the same tree." Eletto sighed. "It’s sort of like hanging out with an old friend, if that makes sense. It’s about the only thing around me that’s actually older than I am."

"Why does that figure?" McCoy shook his head. "Look, we can gab about the plants and trees later, Grandpa. Let’s get down to business. What’s the problem?"

Standing, Eletto moved toward the elevator. "It’s a bit of a story. Let’s get somewhere we can all sit down, and I can offer you some refreshment."

The Vulcan and the three Humans climbed into what looked like an old style elevator, but functioned like a modern turbolift. Moments later, they debarked into a large area, filled with tables and chairs. On one side, there was what looked like a food kiosk. On the other, there was what appeared to be the front desk of a fancy hotel. Eletto went over to the food kiosk, returning with a tray full of comestibles, a flagon of water and a second one of coffee. "Sit down, please, and help yourself. This used to be the water storage and recycling area. With modern life support systems, we didn’t need the water storage, and with the occasional shipload of tourists coming through, we remodeled it into accommodations and such."

Eletto sat down, pouring himself a cup of coffee. "Here’s the problem in a nutshell, gentlemen. I believe that Kahla is suffering some sort of bizarre plague again. The medical team on the surface agrees. We’re stumped, and frankly we’re in dire need of help."

"I thought you said this would take some explaining, Giac," Kirk said. "Correct me if I’m wrong, Bones, but this just sounds like no one has quite found the right antibiotic or vaccine."

"Medicine isn’t always that simple, Jim." McCoy turned to face Eletto. "Given that you yelled for help, Grandpa, I’m willing to bet that there’s more to the story than just that."

"Unfortunately. To begin with, we’re still trying to figure out what the causative agent is. It all started, oh, four or five weeks ago. I was up here on the platform, with a group of historians who were using me as a tool to understand my era. We’d been having some pretty involved discussions, frankly, and I’d been showing them around the ship—a couple were into the history of pre-warp space flight technology and really wanted to look at the nuts and bolts—when Doug called from the surface. A couple of people had died suddenly a couple of days after being given Neokef for a simple bacterial throat infection, and he was concerned."

"I believe, Doctor Eletto," Spock interjected, "That one in approximately 47,369 individuals given Neokef will suffer a severe allergic reaction. If they are not near adequate medical help, it is not uncommon for the reaction to be fatal."

Nodding, Eletto went on. "As always, Spock, you’re absolutely correct. However, neither of them died from an allergic reaction. One of them died from what looked exactly like a severe case of encephalomalacia. On autopsy later, the poor kid’s brain had pretty much liquefied. The other one suddenly developed a severe enough immunosuppression that the Neokef couldn’t eradicate the throat infection. Without any immune response to keep it in check, the throat infection ended up all through the poor fellow’s body, and we couldn’t do a thing to stop it. The man didn’t have a leukocyte to his name. It was bizarre."

"Grandpa, I realize that that’s not something anyone else has seen happen with Neokef, but weird things do happen, once in a while." McCoy grinned wickedly. "Face it, Giac, you’re living proof of that."

"Keep your seat belt fastened, Leonard. It gets worse. When Doug called, there were a dozen or more other people stricken, all of whom ultimately have died. All of them had been put on antibiotics within twenty-four hours of the first two victims, not all of them Neokef, nor all of them for throat infections. The only other thing I could find that they had in common is that they live in Kahla City, which didn’t really help much, given that almost two-thirds of the planet’s population still lives there." Eletto swallowed another mouthful of coffee. "Among other things, Doug was calling me to let me know that I needed to stay up here until it got sorted out, and to keep the visiting historians from going to the surface. We both figured it was just some unfamiliar microbe that was producing a weird, severely cytocidal toxin. Like you said, Captain Kirk, it looked like nothing more than identifying the cause and finding the right choice or combination of antibiotics. Temporary quarantine seemed to be the answer."

"Giac," Kirk asked, "Are you sure that Doug’s not been, ah, doing any experiments?"

Eletto shook his head. "Not a chance. He’s been much too busy. In case you’ve forgotten, last time you were here we were starting to work the kinks out of his medical breakthrough. Ended up, Iaffrey stayed here to help with building the manufacturing capacity to produce the antisense virion, and Oti came back with her husband Zander. Zander, apparently, is one of Centaurus’ leading medical microbiologists, and we needed him to help us do the job. Galori ended up marrying Doug, making Doug grandfather to Anaper and Zander’s firstborn child, little Giac. He was the…" Eletto choked and looked away for a second. "Little Giac was the first victim, Kirk. Work it out from there."

"I’m sorry," Kirk apologized. "I didn’t realize."

"It’s okay; you couldn’t have." Eletto took a moment or two to compose himself. "Anyhow, in the ensuing weeks, there have been over two hundred fifty deaths, and there have been deaths outside of Kahla City, now, probably thirty or so. Folks are terrified."

"Would I be accurate in assuming that you have gone through the epidemiologic studies needed?"

"Yes, Spock. And I’ve personally gone over every autopsy report, every clinical record, every recorded scan, and every culture done. The initial infections have ranged from throat infections and earaches through skin infections, bladder infections, dental abscesses, sinus infections and pneumonia. That’s what finally made me call you, Leonard, and convinced Doug to twist Aaron del Ander’s arm to get him to send out the emergency distress call. Other than the use of any one of a dozen antibiotics, there’s just no common thread that any of us can find. There wasn’t even a common infecting agent, as far as we have been able to determine. Believe me, I’ve looked. Hard."

The four sat silently for a few minutes, staring at each other. Finally, Spock broke the silence. "I am curious to know what you expect of us, Giac. We do not perform miracles."

Eletto shrugged. "I’m not sure myself, really. I guess I’m hoping your different perspective will see something that I’ve missed, like mine did for you guys when the shoe was on the other foot. Somewhere, there’s got to be a common thread, somewhere. I’ve just been too blind to see it."

"We’ll do the best we can," Kirk promised. "All I can promise is that we’ll try." He stood up, obviously intent on getting the ball rolling.

Eletto stood, extending his hand. "From what I’ve learned about you three and your crew, Captain, that’s the best the Federation can offer. I am honored to have been rescued by you and your crew." He turned to face Spock. "Spock, I’m not sure what you did to me last time we met, but thank you, too. Whatever it was, you gave me back my Cherokee background with a clarity I thought I’d never have again."

"It was all there, Adini Noquisi," Spock responded, purposely using Eletto’s Cherokee name. "I did nothing but give you what you already owned."

"Now don’t you get maudlin with me, Grandpa," McCoy snapped, a look of mock sternness on his face. "I was just doing my job."

Eletto picked McCoy up in a bear hug. "Yeah, yeah, I know, Leonard. And all Shakespeare did was string words together."

"Well, it’s no cause to break my ribs. Now put me down, will you?"

Eletto complied; both men wore smiles. "We’ll get the data transferred to the Enterprise shortly. Aaron’s probably working on it as we speak. Is there anything else you’ll need?"

Kirk looked at Spock and McCoy. Both shook their heads. "It doesn’t look like it, Giac. We’d better get back to the Enterprise and get to work."

Eletto nodded. "Thank you, gentlebeings. I’ll be here if you need me."

The three stood near each other. Kirk flipped his communicator open. "Scotty, three to beam aboard."

*****

It was almost at the end of his shift that McCoy felt someone shaking his shoulder. He looked up into M’Benga’s face. "What’s up, Ben? You didn’t need to sneak up on me, you know."

"I didn’t, you hard-headed, Southern bandicoot. I called twice from the door, then came lumbering in like a bull seal on the beach. You didn’t twitch a muscle. Do you realize how long you’ve been hunched over that infernal readout?"

"Couple hours, maybe. It’s not even time for lunch, yet, Ben."

"Not time for lunch, he says." M’Benga slapped his palm against his forehead in frustration. "You’re dead right it’s not time for lunch. You missed lunch, Leonard; it’s time for supper. In less than three minutes, Harrison Davids is going to come out of the turbolift and take Sickbay over for the night. You need to take a break, man, before you burn out your last functioning synapse. Doctor’s orders."

McCoy looked at the clock he’d been ignoring, and realized M’Benga was right. Stiff from the prolonged near immobility, he levered himself out of the chair. "If you put it that way, I guess I’ll have to comply." McCoy gestured at the screen. "This is the sum total of what I’ve learned. Before we go, see if you can make any sense out of it."

Stooping slightly, to get a clearer look at the screen, the Zulu stood still for a moment, reading, before he straightened up. "All I can tell is that there’s absolutely no correlation between the infecting organism and the devastation that results. That, we already knew. There seems to be a weak correlation between the class of antibiotic used and the particular form of mayhem that ensues, which is news, but it’s such a weak correlation that it’s almost worthless. For a whole day hunched over a readout, that’s pretty slim progress." Behind him, M’Benga heard the turbolift. "If you want, you can come back to it in an hour or two. You can even leave the fool thing on the page you’re on. But for now, get away from it."

Davids came to the door, apparently oblivious to the conversation. "Doctor McCoy, are you feeling okay? You look, ah, something less than your usual self." He started to bring his mediscanner into play.

"Oh, put that thing away, Hardav," McCoy snapped half-heartedly. "Ben’s already intervened and read me the riot act. I’m famished, that’s all. C’mon, Ben. Let’s get something to eat."

Hardav backed out of the way. "Bon appetite, gentlemen!" As the two doctors headed to the turbolift, he busied himself at his desk.

Once they were gone, Hardav walked over to McCoy’s readout. As he had hoped, they had left it active and keyed into the Kahla data. Smiling to himself, he set his mediscanner up to warn him of any impending arrivals and began cruising through the data.

By the time McCoy returned to take over for the day, Davids had run through the data to his own satisfaction, and restored the readout to its initial state. "Good evening, Doctor McCoy. You’re certainly looking better than when I last saw you."

"Morning, Hardav. I feel much better, too. I’d planned to come back to work on the Kahla plague, but M’Benga talked me out of it."

Davids nodded. "Doctor M’Benga can be very persuasive. The fact that he signed out an oral dose of prolethene is probably irrelevant."

"That man’s been hanging around you too long, Hardav." McCoy rolled his eyes. "I thought that julep tasted a little funny."

"Rumor reaches me that Doctor Eletto is on the Jovian Platform," Davids said, changing the subject. "Would it be permissible to pay him a visit?"

"I don’t see why not, Hardav. He’s got the whole thing to himself until the problem’s solved, so he’d probably enjoy the company." McCoy ran his eye down his day’s tasks. "You’d better skedaddle before I stick you with half of this morning’s load."

Picking up his medical tricorder, the PA beat a mock-hasty retreat to the turbolift. "Can’t have that! Wouldn’t want Doctor Eletto to die of loneliness."

Hardav made his way to the transporter deck and transported to the Jovian Platform. He looked around himself. The area under the transparent aluminum dome had indeed been transformed. Although the oak tree dominated much of the area, its dominance was rivaled by a pond that covered almost a quarter of the surface. On a rock by the lake sat an individual with his back to Hardav. Knowing it could only be Giac, Hardav called out, "Hey, you! You have a permit to fish in that lake?"

Eletto jumped to his feet, almost dropping his pole. "Hardav! Good to see you’ve stayed out of the brig. You’re just in time for breakfast, or for you, supper." Pulling a stringer with a couple of good-sized fish out of the water, Eletto headed toward the PA. "It’ll only take a few minutes to get ‘em cooked up. You like hashed browns?"

"Sure. What’s the catch of the day?"

"Special strain of carp. Don’t ask what they feed on; they’ll taste better that way."

"I know what carp feed on; doesn’t bother me a bit." Davids followed Eletto, pitching in on the cooking. "How’re you doing, Giac?"

Eletto shrugged. "Not bad, really, but I’m starting to get a little bored. I mean, after a couple of years, I feel that I’ve pretty well caught up on things, and between ‘Beat the Reaper’ and a few other things, I’m up to par in medicine. Anymore, I spend an inordinate amount of time being talked to by historians, or being treated like some sort of celebrity on Kahla. Give me a year or two, and I think the itch to go exploring is going to be overwhelming."

"I understand, Giac. I’ll remember that; maybe Starfleet will remember it needs you, some day." Davids gave Eletto a skillet who put it on the stove.

For a while, both men concentrated on cooking. Finally, Eletto looked up. "I’m willing to bet this isn’t just a social call. What’s on your mind?"

Hardav speared a piece of fish, pulling it out of the hot grease and sliding it on a plate. "Doctor McCoy left the data from your latest crisis unguarded, Giac. I spent most of my shift looking it over. We need to talk. I want to bounce a thought or two off you before I make my report."

Eletto filled his own plate and joined the PA at a table. "You talk; I’ll listen. What happened?"

"I hopped outside the box, what else? I may have the kernel of an answer, but..." Hardav paused, a loaded fork halfway between his plate and his mouth. "But it is going to have to wait until I’m done eating. We don’t get grub this fresh on the Enterprise, trust me. Then we visit the data again, this time from my angle." The fork load disappeared.

Eletto shoveled the last of the hash browns onto Hardav’s plate. "I remember, trust me. How about some input between bites?"

Hardav swallowed. "Wonder if we could get a fish pond like yours going on the Enterprise?"

"It’d be tough. It would probably take up too much space. What’ve you found?" It was clear Eletto wasn’t about to be diverted.

"I’m not totally sure, Giac, but I think the problem is in the gut flora. As far as I could tell, that was the one place nobody had looked. Seems to me when no one else can find the answer, the best place to look is where the others haven’t. That’s where I found a novel bacterium, at least on all the scans that included the gut at sufficient resolution. Now, I realize that I should expect some local bacteria to become gut commensals; that’s not what bothers me."

"You’re killing me with suspense, man." Giac menaced his companion with a spoon. "Ve haff vays of making you talk, Mister Daffidz, und ve can make you vish you had more to tell..."

Hardav shook his head. "Torturing me with a hokey fake accent isn’t one of ‘em. Look, let’s go to the data, okay? I want you as unbiased as possible when you see it."

Noticing that the PA had finished eating, Eletto cleared the table. "There’s a readout at the desk over there—a modern one. Follow me."

The pair stationed themselves in front of the readout. Davids began sorting through the data. "See?" He pointed. "Not very intense, but it’s clearly there. Ever seen anything like it?"

"No, I haven’t." Eletto moved closer. "Nor has the medical database, or it would have given us more than it has. Not even anything vaguely similar, even at the genus or family level." He nudged Davids to one side.

"I’d have thought you’d have programmed it to put the unknowns right at the top of the readout, especially the least familiar stuff."

"Still too many unfamiliar microbes, Hardav. It’d fill up the display. This colony’s not all that mature." Giac was clearly engrossed in the readout. "Give me a sec, here. Need to find something."

"Look, if you’re trying to find out if this microbe shows up elsewhere, I can save you the effort: it’s there on every scan that includes the abdomen; it doesn’t show up anywhere else. I’ve checked that already."

Eletto shook his head. "I figured that out; you’d have already told me if it were otherwise." He keyed up another record. "Ah, here it is."

"What’s special about this scan?" Davids moved back in, looking over Giac’s shoulder.

"Highest resolution scan of the abdomen in the bunch. Best bet for finding some data on the bacterial structure." Eletto ran through the data a little further. "Here. Look at this." He stepped away from the readout, letting Hardav take his place.

As Hardav stared at the screen, digesting the significance of what he was seeing, he heard Giac at the communications console. "Yeah, sorry to interrupt breakfast, but it’s important. No, not a solution yet, Doug, but maybe the first break. Ready up for receiving; a marked file’s coming." Eletto turned to Hardav. "Hit mark, then transmit, will you?" Without comment, the PA obeyed; Eletto continued talking to Doug. "I want Zander’s opinion, too. Then drag him out of the shower, or turn the hot water on full blast somewhere to drive him out." There was a brief silence. "Yes, it is that important, Zander. Look at the screen. What do you two make of it? Great, I was afraid of that. I was hoping you’d disagree with me. Doug, I know you too well to believe anything else, but under the circumstances, Zander and I may be the only ones who do, at least until it’s all tracked down. For pity’s sake, try doing the obvious for once—do stool cultures on everyone in sight, until you find a positive, and get genome studies going. Oh yeah? You want me to sic Galori and Anaper on you? Good. I knew you’d see it my way if I reasoned with you. No, not yet, just Hardav as far as I know. Okay. Later, when you’ve more data. Eh? Oh, sorry. Forgot." He turned to Hardav again. "They want the scan signature of the presumed causative bacterium. Could you transmit it?"

"Keyed up and transmitted," Davids responded.

Eletto returned to his discussion. "Got it? Good. No kidding it’s bizarre. Anything else? I’ll check back in eight hours, then. Let me know if you find anything sooner. Bye."

His back to the readout, Davids stared pointedly at Eletto. "Mind explaining what you guys are thinking? Your end of the conversation wasn’t exactly enlightening."

"I thought you’d already figured it out, Hardav. The microbe is artificial, and clearly a weapon. Doug and Zander are going to get that confirmed as quickly as possible, but we’re 99.44% sure. It appears that Kahla is under attack." As he spoke, Giac realized that Hardav had a mediscanner focused on him. "Oh, put that thing away, Hardav. I feel fine."

"You won’t be fine if you take an antibiotic, Giac." Davids put his mediscanner back on his belt. "You’re carrying the microbe, too." He made his way to the communications console. "That means Doctor McCoy, Spock, Captain Kirk, and potentially anyone they’ve come in contact with is potentially infected, too."

Eletto paled. "Then so are the historians from several weeks ago, and who knows who all else. You get McCoy. I’ve got to call del Anders."

*****

U.S.S. Enterprise, NCC-1701-A
Medical Log, Stardate 9161.8
Doctor Leonard McCoy dictating

The Enterprise is now under quarantine. The microbe that has been the cause of all the trouble has been isolated and its DNA tentatively sequenced. Until its source is clearly known, Douglas Eletto has gone into voluntary house arrest. The bacterium is apparently an artificial organism...

Zander Oti sat across a table from Doctor McCoy. "It is most remarkable, Doctor McCoy. Any member of several classes of antibiotics will trigger production of any one of several apoptosis peptides."

"It’s a sweet design, all right, diabolically sweet. Look—here." McCoy’s finger jabbed at the readout. "The area coding the apoptosis peptide has a high recombination rate, according to the sequence analysis. Until the killer system is triggered, it switches from the signal for one tissue to self-destruct to the signal for another. You get a randomly shifting target until the trigger is pulled, making it all the harder to catch on to what’s happening."

"It’s a Klingon Casino, but with all the phasers charged, not just one of them." Zander remained focused on the screen for a little longer. "This part of the genome needs modeled carefully on the biocomputer, but it almost looks like a DNA version of a count-down timer. After a certain number of divisions, the kill mechanism gets activated, but seems quiescent until then. Absolutely remarkable, if that’s what it is; I have not seen its like."

"It’s utterly unprecedented, and brilliant, to boot." McCoy agreed. "All we have to do is figure out how to eradicate it without killing the Human carrying it, and find out where it came from so we can make sure we plug the supply. That’s all."

"Finding where it came from may be easier spoken than managed. There is but little data with which to work. At least it is clearly incapable of surviving in the environment, and we now know which antibiotics we can safely and effectively use to eradicate the microbe. For that, at least, let us be thankful."

"Believe me, I am, and I’m thankful we’ve got plenty of most of what we’ll need." For a moment, McCoy was pensive. "What sticks in my craw is that the particular choice of antibiotics used to trigger the killer genes should mean something." He sat at another readout. "That, and that genetic timer must hold something useful."

The silence was only broken by the sounds of McCoy working with his readout. Finally, he straightened up. "Between forty and fifty-five days, I’d say, depending on nutrient supply. Maybe as long as sixty, but I doubt it."

"Would you tell me what this period of time of which you speak might be?" It was clear that Zander was puzzled.

"The length of time that the computer estimates it would take for your little DNA timer to go off." McCoy backed away from the readout. "Off hand, the next trick should be to ascertain what candidates there are for being a source for all this. I guess it’s time to call del Anders, and see what we can find."

"There should be no need, Doctor McCoy. The only event of significance in the window you have suggested is the arrival of the Cutty Sark. It was a modest sized, independent trading vessel that specialized in artifacts from extinct civilizations. They ship had stopped here to resupply before heading out to territory unknown, and apparently was limping back after being damaged." Zander’s brow furrowed for a moment, in an effort to dredge up details. "As I recall it, the belief was that there had been an explosion in a hold; the guess was that they’d inadvertently picked up a bomb or a mine, thinking it was something else. Only a couple of the crew survived. We did what we could, but their injuries were too much."

"Did anyone board the ship?"

"I don’t think so, but on that, you would have to check records. I seem to remember that the ship’s navigation system was so badly damaged that we couldn’t get it into a parking orbit. Makes it unlikely that anyone boarded; I think the survivors had to be transported to the rescue ship. Now that I think of it, they were in environmental suits, and had suffered some major brain damage."

"You’re just a wealth of cheerful news, Zander. A ship from who knows where, with no survivors to tell us anything, that’s headed off in some unknown direction." McCoy triggered the communications. "Spock?"

"How may I help you, Doctor McCoy?"

"We need you to track down a ship..."

*****

Captain’s Log, Stardate 9164.6
Captain James Kirk recording

With the identification of the cause of the plague on Kahla (Gamma Virginis II), and of several medications that will safely combat the artificial organism that has been wreaking the havoc, the medical portion of this problem is essentially resolved, and Douglas Eletto is out of house arrest. All that remains to be done is to discover the source of the microbe, and ensure that it will not produce and disseminate others like it. We have located the wreckage of the Cutty Sark; hopefully the ship’s recorder will be sufficiently intact to offer an answer.

Spock and McCoy materialized on the bridge of the Cutty Sark, in full environmental suits. Both beings brought their scanners into play.

The scene around them was grim. Several dead crewmen were strewn on the floor. Most, if not all, of the control areas had been severely damaged. At one end of the bridge, the door in the airlock controlling access to the rest of the ship had been sheared loose from its hinges and was hanging uselessly from a bent and twisted locking bar.

After studying his mediscanner briefly, McCoy knelt beside one of the cadavers, inspecting it carefully. Gently, he rolled the dead man onto his back. From chin to groin, there was a surgically precise incision that laid the contents of the trunk open for inspection. Samples of each organ had been removed with equal precision. Through the man’s forehead, a similar wound exposed the brain, which had suffered a like fate.

The doctor restored the dead man to his original position. "It almost looks like someone did an autopsy, Spock, at least a partial one." He stood up. "Judging from the pattern of blood stain on what’s left of his clothing, whoever did it hadn’t the courtesy to wait until he was dead before they did it, either." He consulted his mediscanner again. "Looks like the rest of the crew suffered the same way."

"Indeed, Doctor." Spock straightened up from under the navigation console, a modest sized box dangling numerous wires in one hand. "The ship’s control systems have all been cut and connected to this, which I conjecture to be an automated control system." The Vulcan studied his tricorder briefly. "Thankfully, the ship’s recorder appears undamaged." Gently, the Vulcan disengaged the recorder. He inspected it carefully.

"Come on, Spock. I want to check Sickbay."

"In ships of this size, Doctor, the recorder would have the logs from Sickbay and Engineering as well as the captain’s log, Doctor."

"Humor me. The log is someone else’s observations; I prefer to look for myself. It’s easier to find what you need to know when you’ve got an idea of what your looking for, which I think I do. Come on." McCoy began to move off the bridge. Resigned, the Vulcan followed, as much to be ready to rescue his companion as anything else. Spock paused as he went through the lock, studying it and the walls of the corridor briefly.

McCoy turned, surprised at the delay. "What’s piqued that Vulcan curiosity of yours?"

"The dissonance between the violence suffered by the door and the comparatively intact walls of this corridor."

"Your point?"

"It is incompatible with an explosion removing the door, Doctor." The Vulcan inspected the walls more closely. "Here: there are scratches, and an outward bowing of the wall. It would appear that some mechanism braced itself here while it rammed the airlock door open." He moved a few meters further, to another airtight door that had been subjected to similar treatment. "This appears to have been a brutally thorough assault."

"Brutal, yes, and grisly—but remember, there were two survivors. At the moment, that doesn’t exactly fit with the rest of the picture. I’ve got a point or two I want to check, to see if I can confirm my guess and make sense of this mess."

Only a few moments’ walk was needed to locate what passed for Sickbay on the trading ship: a small cabin with a pair of bunks and a couple of cabinets that had originally been filled with medications, instruments and the like. It had clearly been looted. McCoy rummaged through what was left, to emerge, triumphantly clutching a sheet of paper. "Here it is! And it proves we’re on the right track."

Behind the transparent aluminum faceplate of his protective suit, one of the Vulcan’s eyebrows lifted. "Indeed. Precisely what is on that sheet of paper?"

"Look for yourself, Spock. I need to scan this area." McCoy lifted his mediscanner. "Mind stepping out of here?"

The Vulcan complied without comment, to be followed by his companion. After a few more moments, McCoy returned his tricorder to its belt clip. "Not a trace of the microbe anywhere. Interesting."

"Remarkable. And the listing of antibiotics available tallies exactly with the ones by which the microbe was potentially triggered. It is highly unlikely that this is a coincidence." Spock consulted his tricorder again. "I would be interested in the theory you claim to be confirming."

"I’m pretty confident I’ve confirmed it, Spock." McCoy shook his head. "Look at it this way: if you wanted to design a microbe to do major damage to a minimally familiar life form, how would you go about it? I’d get a sampling of as many major tissues as I could, from every individual I could, so that I could study the stuff in culture, and work out how to destroy the tissue. I’d take bacteria from the creatures, and redesign them to produce any one of a handful of lethal somethings, and I’d trigger the homeobox that produced the lethal whatever with a medication that would be familiar and used for an infection."

"The pattern of damage to the remaining cadavers certainly matches your theory, Doctor. Leaving two crewmembers alive, but incapacitated, to act as vectors of the disease is also logical, and consistent with the data." The Vulcan paused for a moment, deep in thought. "It is also logical to suppose that whoever constructed the bacterium reversed the travel trajectory in the ship’s navigational log, bringing the ship back to its last port of call. At this point, it appears that the part of the puzzle relevant to Kahla is resolved. The next task will be to locate the source, and neutralize it. Unless you have anything else you wish to check, I suspect it would be prudent to return to the Enterprise."

"Might as well, Spock. We can tow the ship back to Kahla where they can complete the investigation. They’ll want to deal with the crew’s personal effects, too."

Spock toggled the suit’s communicator. "Captain Scott, two to beam to decontamination."

The two beings disappeared into the transporter’s sparkle.

*****

"Location, Lieutenant Jaeger?"

"Approaching one light year from the position of the Cutty Sark before the log indicates the incident occurred, Captain."

For a moment, Kirk pondered his options. "Drop to sublight, and maintain current position, Lieutenant. Spock, what’s showing up on scan?"

The Vulcan looked up. "There is a stellar system bearing 021 mark 4, at 1.224 light years distance; G0 dwarf, four gas giants, three ice planets, four rock bodies, two meteor belts. Fourth rock body shows signs of an extinct civilization. Bearing 351 mark 9, at 3.087 light years distance is a derelict; I am attempting to identify it."

"We’re outside the Federation, Spock, in unexplored territory." Kirk shook his head. "Surely you don’t expect to identify it."

Spock turned to face Kirk. "Ordinarily, I would not expect to be able to do so. Given that the derelict is 12.71 kilometers across, and 1.945 kilometers in greatest thickness, I conjecture that it may be a flying city of the Jablisch culture. Utterly fascinating."

"I thought the Jablisch were a myth, sort of the interstellar version of the boogie man," Jaeger responded. "They’d come on their flying planet, steal everything of value, brutalize the population, trash whatever was left and fly off looking for other places to assault."

"That had been the prevailing opinion, Lieutenant Jaeger." Spock turned to face her. "However, recent archeological findings suggest otherwise. Among the most telling was the observation that, making allowance for transit time, the planets with Jablisch myths are very nearly in a line. Almost equally telling is the discovery of numerous looted, extinct civilizations that line up similarly. Projecting the line of known Jablisch contacts would intersect the volume of space in which this star system rests."

Kirk’s face registered a touch of surprise. "I thought they were just a myth myself, Spock. What else is known about them?"

"Based on the evidence from the extant and extinct civilizations, the Jablisch were raiders, perhaps somewhat similar to the Terran Vikings. Although they do not appear to have mastered warp drive, they traveled at near light speeds, presumably using a version of impulse drive. One of their scout ships would arrive at a planet with an industrial, pre-spaceflight, civilization. Having scouted it out, the ship would return to the city, which would move into orbit around the planet. The Jablish would enslave the population and loot the planet of refined metals, livestock, crops and petrochemicals. Generally between fifty and seventy-five years later, a second city would repeat the process; later, a third and occasionally a fourth visitation would happen at similar intervals. Both myth and archeological evidence indicate they were humanoid. Little else is known."

"Status of the derelict?" Kirk demanded.

"No evidence of life signs, Captain." Spock consulted his science console. "No evidence of power generation or use. It is no apparent threat."

"Then our business is elsewhere. Shields up. Yellow alert. Jaeger, take us to the planet." Kirk fixed his eyes on the main viewscreen. "Half warp, Lieutenant. Spock, maintain vigilance. I’m not interested in being caught unprepared, like the Cutty Sark was."

Except for the chatter of the various consoles and the periodic computer reminder that the ship was on yellow alert, the bridge remained silent. Slowly, the planet grew larger on the viewer.

"Evidence of mechanical activity on the planetary surface, but still no life sign," Spock announced levelly. "Intruder, bearing 179 mark 58, closing rapidly."

"On screen with it, Spock. Let’s see what we’re up against."

In the center of the screen appeared a dull, grayish object, festooned with arms, some that looked designed for gripping in one way or another, others for puncturing or tearing. There was no sign of finesse or subtlety about it; it was clearly designed for sheer, aggressive, brute strength and little else. As it approached, it grew larger and more menacing in appearance. Suddenly, it was surrounded in sparks, its forward motion halted by the shields. A second time, it moved forward, more rapidly than before. The shield stopped it again, showering its ceramic exterior with sparks. With the third attempt, the ceramic fractured on its impact against the shields. The craft sat motionless, just outside the shield’s perimeter.

"Well, I suppose we know what the machine that assaulted the Cutty Sark probably was, now," Kirk commented dryly. "At least we’ve been able to stop it. I…"

"Captain, it appears that more of the same craft are approaching," Spock interrupted.

"How many, Spock?"

"It is difficult to estimate with precision; they are in tight formation. Not less than a hundred and fifty. Certainly more than the shields can handle for any length of time."

"Mainviewer. Estimated time to contact?"

"Six point three minutes, Captain."

"Mister Chekov, lock on photon torpedoes; tight dispersion. Fire when ready."

The Enterprise lurched as the torpedoes launched. An instant later, there was a fireball on screen, then nothing but the stars.

Again, the Vulcan’s voice broke the tense silence of the bridge. "More coming, Captain, from multiple directions. They are too numerous to handle. I conjecture that this may be an automated defense system to deal with future assaults from the Jablisch." Spock looked up from the console. "Judging from the derelict, it was effective."

"That would explain the artificial organism, too, I expect: send a couple victims back on the scout ship, and infect the whole city, maybe even wipe out the culture. Can you triangulate the control center?"

"I believe your conjecture has merit. I have located the control center, Captain. Two point two minutes to impact."

"They’re probably not programmed to allow for warp drive. Jaeger, warp five, straight up from the ecliptic for thirty seconds... now."

The Enterprise’s engines briefly roared into life. Below the ship, the craft that had been targeting the Enterprise were unable to stop before colliding with each other. All but a few were destroyed, but the remaining few rapidly located the Enterprise and began accelerating toward it. More joined them even as the bridge crew watched.

"Evasive maneuvers, Jaeger." Kirk turned to Spock. "Spock, is there a power supply on the planet we can target?"

"The control center appears to run off geothermal power; both the command center and its power supply are heavily armored and deep beneath the planet’s surface. It does not appear feasible."

"How?"

"There’s a dense cluster of large bodies," Jaeger responded, deftly maintaining evasive tactics. "Warp into it and hide. It won’t fool them for long, but it will buy us time."

"Do it, Jaeger." Kirk turned to Spock as the Enterprise leapt into its temporary concealment. "How fast is that electronic guidance system that’s sending these assault devices?"

The chief science officer consulted his display. "Comparatively slow, Captain. Judging from the control system inserted in the Cutty Sark, it is a primitive version of silicon chip technology. However, the central control appears to target the assault devices; from there on in, they appear autonomous."

"And fairly mindless. They’re not the real problem. How long would an image persist on the control system’s sensors?"

"There are too many variables to be sure. On the order of twenty to forty milliseconds."

"Good. Jaeger, can you shuttle the Enterprise between, say, nine or ten different locations fast enough to make us an almost impossible target, but slowly enough to make this computer still see a continuous image at each of the places?"

Jaeger smiled thinly. "If Captain Scott doesn’t have a fit over it, Captain, I believe I can set up a moving three dimensional pattern, with the Enterprise being the pea in... Well, using warp two, one of about twenty shells. Minimum separation would be about twenty-five kilometers; it could stretched to a hundred kilometers or more with minimal trouble."

"I do not comprehend your plan, Captain," Spock remarked, clearly somewhat concerned.

"The computer driving this system is slow and, by modern standards, feeble. If we can overload it, or perhaps confuse it badly enough, I’m hoping it will shut down."

The Vulcan nodded. "I see. Might I suggest one further refinement?"

"I’m all ears, Spock."

The Vulcan paused as he tried to determine whether or not his captain was joking during such a serious crisis. "The central control system will unquestionably target the images with the attack drones. If the image under attack vanished just before the drones arrived, it would dramatically increase the stress on a machine as simple as we appear to be facing. It might also render some of the drones inoperable. There must be a limit to the supply."

Kirk turned back to face the helm. "What about it, Lieutenant?"

"The old shell game is bad enough. Have shells disappear in one place and reappear in another, and you’ve got the makings of a real nightmare." Jaeger developed a wicked glint in her eyes. "This has some delightful possibilities, Captain."

"It should also be possible to get some pot shots at them, Captain," Chekov offered. "We’ll know the position of the targets precisely. A short phaser burst triggered when the Enterprise arrives at the proper location is quite feasible."

"Is it possible to program in hitting the same target from several directions, Commander?" Kirk was rapidly warming to the plan.

"No problem, sir. Also, multiple targets from a single site." He turned to Jaeger. "The navigational program ready?"

"Ready and waiting."

Chekov concentrated on his panel for a moment. "Sweet scheme, Gretchen. Weapons ready to roll, Captain."

"The attack drones seem to have located us, Captain," Spock interjected.

"Jaeger," Kirk ordered, "Take us back to the planet, and start the shell game. Chekov, keep shooting. Spock, monitor that control center."

"Yes sir." There was an almost frightening enthusiasm in Chekov and Jaeger’s voices as they answered in unison.

Almost immediately, the Enterprise was above the planet again. A swarm of attack drones appeared on the viewscreen, zeroing in as before. Just before they hit the shields, the viewscreen showed two images of the Enterprise, firing on the drones. More drones deployed, assaulting the images. Each cluster of drones suffered as had the first. The viewscreen showed four images of the Enterprise. With the next group of drones, there were suddenly eight ghostly images.

"Spock, status of the control center?"

"It appears strained, Captain, but not on the verge of collapse." Spock turned to Jaeger. "Lieutenant, you specified a limit of twenty at warp two. I conjecture that more images would be possible at higher warp speed; certainly, the load of tracking more images would be considerably more taxing to the targeting computer. If we desisted from using the phasers, is it possible to manage one hundred and twenty images?"

Jaeger’s brow furrowed for a moment. "Possible, but not for long, I’m afraid. Shuttling like this is a lot more strain on the drives; we might be able to push it to warp five, tops."

Without waiting for Spock to answer, Kirk interrupted. "Do it, Lieutenant."

Jaeger made no answer; she just frowned over the controls, programming in a new set of navigational commands. Suddenly, the screen exploded with images of the Enterprise, some enduring for several seconds to minutes, others flickering in and out of existence over longer and shorter periods.

"Captain," Scotty’s voice burred over the communications system, "I don’t mean t’question the madcap goin’s on, but my engines won’t take much more of this warp-drive hop-scotch."

"Spock?"

"The control system is starting to show signs of excessive heat generation, Captain. It is just barely keeping up."

"Jaeger, push to warp six, and as many images as it will give us."

"Captain," Spock said levelly, "There are disturbing effects on space-time already becoming visible. Are you sure this is advisable?"

Unable to adequately respond, Kirk ignored Spock’s concerns. "Jaeger, are you ready to go to warp six?"

"Yes, sir. On your order."

"All right, Lieutenant. Give it three minutes, then get us out of the drones’ reach."

The mainviewer was suddenly full of images of the Enterprise, shifting and dancing like confetti in a cyclone. Abruptly, the screen cleared, showing the planet far below.

"Current position, 14.3 AU above the system’s ecliptic, Captain," Jaeger announced, a hint of relief and triumph in her voice.

"Spock, status of the drones and the control center?"

"The drones that have been deployed appear incapacitated, Captain. Central control is damaged, but still marginally functional."

Kirk nodded pensively. "Scotty, Engineering report?"

"Warp drive is damaged, Captain; it’ll be a couple of days before she’ll give you more than warp one and a half."

"Thank you, Scotty." Kirk stared at the main viewscreen, as if expecting the stars to give him an answer. "Spock, how much would it take to push this control system over the edge?"

"It is difficult to be precise, Captain. At the moment, not much—but the machine appears to have the capacity for self-repair."

"Jaeger, can you program a sequence that will generate an image that appears to be approaching the planet at a little bit faster than the speed of light?"

"Easily, Captain. I could put a final step at the end to take the Enterprise out of their sensor range, too." Jaeger tapped on the console briefly. "I could even loop it, and come straight in at the central computer from a different angle each time. All we’d lack is Doppler shifting."

"The lack of Doppler shift may increase the effectiveness of the maneuver, Captain," Spock added. "The contradiction between the movement of the image and the Doppler shift may cause the system to get caught in an endless oscillation loop."

"Do it, Jaeger," Kirk ordered. "Spock, let me know as soon as that system crashes."

The mainviewer was filled with the image of the planet exploding on it. A handful of the attack drones tried to zero in on the Enterprise, to no avail. At the instant when it almost seemed that the starship would ram the surface, the image disappeared, then was replaced by a tiny globe that expanded again.

"Heat dissipation in the control computer is increasing dramatically, Captain," Spock announced. "The maneuver appears to be working."

The image continued to cycle. Drones began to collect near the point the Enterprise appeared to be targeting. As the heavy cruiser made its next run, the drones began to streak toward the approaching star ship.

"Captain," Scott’s brogue burred through communications, "This had best be the last pass. I’m not sure that the engines can take much more of..."

There was a sudden noise, followed by Scotty bellowing commands. The image on the mainviewer froze, except for the approach of the attack drones.

"Spock?"

"It appears that the warp drives have failed, Captain," the Vulcan responded. "As has the control system on the planet. It appears, however, that once targeted, the drones are autonomous. And inexorable."

"Commander Chekov, can we take them out with the ship’s weapons?"

"They’re too numerous to get in time with phasers, sir, and too diffuse to take out with photon torpedoes."

"Jaeger, do we have impulse?"

She touched the control surface in front of her. "Some impulse, Captain, but not enough to outrun the drones."

"Four minutes until the first drones impact, Captain."

"Thank you, Spock," Kirk returned. "I’m open to suggestions."

"The drones’ tracking mechanism senses electromagnetic radiation, Captain," Spock offered. "Silicon based sensors are not as robust as more modern ones."

"I think I get the hint, Spock. Commander Chekov, fire a photon torpedo—and then when it’s near the drones, detonate it with phaser fire. Maybe we can blind these obnoxious little drones."

Rapidly, Chekov began pounding the control surface in front of him.

"Two minutes, ten seconds to impact," Spock intoned. The Enterprise shuddered slightly as the photon torpedo took flight.

"Jaeger, the instant that photon torpedo detonates, move us away from the drones as fast as you can."

"One minute, forty seconds."

Chekov’s finger jabbed the control surface one last time. The mainviewer whited out, just as the Enterprise began to move. As the screen cleared, the drones were still approaching. Despite the starship’s retreat, they slowly gained. As they reached the place the Enterprise had abandoned, they rammed into each other, grappling and clawing each other in a great, frenzied, writhing ball.

Around the mass of drones, a number continued to streak toward the Enterprise. Inexorably, they drew closer. Transfixed, the crew watched. One by one, the drones hit the shields, bouncing off into open space.

Kirk realized he had been holding his breath, waiting for the outcome. Slowly, he exhaled. "Are there any more of those drones coming?"

"I do not detect any, Captain. And the control system on the planet remains inoperative."

"Excellent. Engineering. Captain Scott, status report."

"It’ll be at least two, and maybe three days before we’ll have warp drive back, Captain," the Scotsman replied. "And even then, it’ll not be better than warp two. She’s going to need a complete overhaul after this."

Kirk stared at the bottom of the cup he’d emptied while spinning his tale. He refilled it. "As usual, Scotty only took about a quarter of the time to get the Enterprise up to snuff as he said it would, and it was twice as good as he’d said it would be. Spock managed to do a good deal of preliminary work on the planet, particularly the automated system for building bacterial weapons. My guess is that we’ll see some major innovations come out of that system. It wasn’t long after that that an armada of archeologists made their way there to study the planet and the Jablisch flying city."

"But what of the people of the planet, Captain?" Indri’s voice showed clear evidence of puzzlement. "What became of them?"

Kirk shrugged. "I’m not sure, Indri. Spock was convinced that the last visitation by a Jablisch flying city found the planet already dead, except for the system they’d left behind to wreak vengeance on the Jablisch." Pensively, he sipped his coffee. "Spock never really figured out what happened to them; he said that the answer would have to wait for the work of the professional archeologists. But after tonight, I’ve a guess." Kirk paused again.

"C’mon, Cap’n," Reichard cajoled. "Don’t kill me with the suspense. What’s your theory?"

"When you guys got me off on this tale, Indri had observed how nearly universal the contents of humor and graffiti were, both across Human history and humanoid species. Thinking about it tonight, I suspect the same may be true of a lust for vengeance, and its results. I suspect that they’d poured everything they had into building their automated vengeance system. The design, building and testing of the system probably consumed them. Unless, of course, it accidentally backfired, producing a bacterium that wiped them out, but somehow, that doesn’t seem likely to me."

In the distance, a lone coyote bayed at the moon. "Perhaps," Indri suggested, "That is why so many of the Holy Writs agree that vengeance is the sole prerogative of the All-Powerful, All-Knowing One. No mere mortal has the wisdom or the strength to handle it."

"Or to survive it." Kirk looked at the moon. In the distance, the howl of a coyote baying at the moon echoed again. "It makes you wonder what, if anything, we share with other creatures, like that coyote. The poor coyote hasn’t gotten an answer. He almost sounds lonesome to me."