nothing wecan do."

  "How so?"

  "Because that's a precision job, sir. The threads are tapered so thatthe fit will be gas-tight. That's why the threads have aten-thousandth of an inch of soft polyethylene covering the hardsteel, so that when the threads are tight, the polyethylene will actas a seal. Everything in that connection is a precision fitted job.The ends of the tubes are made to be slightly mashed together, so thatthe seals will be tight--they're coated with polyethylene, too. If theoxygen and hydrogen mix, the efficiency of the fuel cell goes down tozero, and you run the chance of an explosion."

  "Show me," Al-Amin said.

  Smith took a pencil out of his pocket and began drawing a crosssection of the connection on the top of the nearby table.

  "Look here, captain, this is the way the two are supposed to fit. Butthey don't, because the male plug can't get far enough into the femalesocket to make the connection. Like this, see?"

  The captain nodded.

  "Well," Smith continued, "there's a thirty-second of an inch clearancethere. If the female had one more turn of thread, the fit would beprefect. As it is, we get no connection. So the screamer doesn'tfunction."

  Al-Amin looked at the drawing. "Odd that there's never been anycomplaint about this error before."

  Jayjay turned another ace. "Not so odd, really."

  All heads turned toward Jayjay.

  "What does that mean?" Smith asked.

  "Just what I said." Jayjay turned another card. "A screamer issupposed to call for help, isn't it? It's only used in a direemergency. Then the only test of the whole unit comes when theoccupants of the spaceship are in danger--as we are. If the thingsdon't work, how could there be any complaint? If we can't get ours towork, will we complain? To whom?

  "How many ships have been reported missing in the past year or so? Allof them presumed lost because of meteor strikes, eh? If a ship is lostand doesn't signal, we presume that it was totally destroyed. If itwasn't, they'd have signaled. As _Mister_ Smith says: See?"

  There was a long silence.

  Jayjay Kelvin turned the last card, saw that he had lost, and beganshuffling the deck.

  * * * * *

  "I think I've got it," Smith said excitedly, several hours later.

  Captain Al-Amin glanced around. Hull was dozing fitfully a few inchesabove the couch. Jayjay Kelvin was still methodically playingsolitaire.

  "Keep your voice down," the captain ordered. "No use giving ourpassengers false hopes. What do you mean, you've got it?"

  "Simple. Real simple. All we have to do is file off the last thread ofthe male plug. Then it will fit into the female." Smith's voice was ahoarse whisper.

  "Won't work," said Jayjay Kelvin from across the room.

  Smith blew up. "How do you know?" he roared. "You sit over theremaking wiseacre remarks and do nothing! Play cards, that's all! Whatdo you know about things like this, _Mister_ Joseph Kelvin? What doesa businessman know about mechanical equipment?"

  "Enough," Jayjay said quietly. "Enough to know that, if you try tofile off the final thread of the male plug, you'll do an uneven job.And that will mean leakage."

  "What do you mean, an uneven job?" Smith was still furious.

  "Trimming off the end of the male plug would have to be done on alathe," Jayjay said, without looking up from his cards. "Otherwise,the fit would be wrong, and the gases would mix. And we would all go_phfft!_ when the mixture blew."

  Smith started to say something, but Jayjay went right on talking."Even if we had a lathe, the male plug doesn't turn, so you'd be outof luck all the way. You can't take the screamers apart withoutwrecking them--not without a machine shop. You're going to have towork on that female connection. She's got a sleeve on her that willturn. Now, if--" Jayjay's voice faded off into silence, and hismanipulations of the cards became purely mechanical.

  "Huh!" Smith said softly. "Just because he's related to KelvinAssociates, he thinks he's hot--" He said the French word again.

  "Is he right?" Captain Al-Amin asked sharply.

  "Well--" Smith rubbed his nose with a forefinger. "Well, yes. I waswrong. We can't do it with a file. It would have to be turned on alathe, and we don't have a lathe. And we don't have any measuringinstruments, either. This is a precision job, as I said. And we don'thave a common ruler aboard, much less a micrometer. Any makeshift jobwill be a failure."

  Captain Al-Amin brooded over that for a moment. Then he looked atJayjay again. "Mr. Kelvin."

  "Yes, captain?" Jayjay didn't look up from the cards in his hands.

  "_Are_ you related to Kelvin Associates?"

  "In a way."

  Al-Amin bit at his lower lip. "Mr. Kelvin, you registered aboard thisship as Joseph Kelvin. May I ask if your middle name is James?"

  After a short pause, Jayjay said: "Yes. It is."

  "Are you _the_ J. J. Kelvin?"

  "Yup. But I'd rather you didn't mention it when we get to Pluto."

  Smith's jaw had slowly sagged during that conversation. Then he closedhis mouth with a snap. "You're Jayjay Kelvin?" he asked, opening hismouth again.

  "That's right."

  "Then I apologize."

  "Accepted," said Jayjay. He wished that Smith hadn't apologized.

  "Why didn't you say so in the first place?" Captain Al-Amin asked.

  "Because I didn't want it known that I was going to Pluto," Kelvinsaid. "And--after the accident happened--I kept quiet because I knowhuman nature."

  Jeffry Hull, who had awakened during the argument, looked at Jayjayand said: "What's human nature got to do with it, Mr. Kelvin?"

  "Nothing, except that if I'd told everyone I was J. J. Kelvin, all ofyou would have been sitting around waiting for me to solve the probleminstead of thinking about it yourselves."

  Hull nodded thoughtfully. "It makes sense, Mr. Kelvin. If they'd knownthat you were ... well ... Mister Spaceship Himself, they'd have letyou do all the thinking. And that would have left you high and dry,wouldn't it?"

  Jayjay put the deck of cards in his pocket. "You're a pretty goodsociologist, after all, Mr. Hull. You're right. Face any group withAuthority--with a capital _A_--and they quit thinking for themselves.And if they do, then the poor slob of an Authority doesn't haveanything to tickle his own brains, so everybody loses."

  "Well, _do_ you have an answer?" Captain Al-Amin asked.

  Jayjay shook his head. "Not yet. I think I've got one coming up, but Iwish you two would go on talking while I think."

  "I'll try," Smith said wryly.

  * * * * *

  The problem was both simple and complex. The female socket lacked onesingle turn of thread to make a perfect connection. A few hundredthsof an inch separated success from disaster.

  Five men, including the unconscious Vandenbosch, were only a fractionof an inch away from death.

  Jayjay Kelvin listened to Smith talk for another half hour, throwingin objections when necessary, but offering no opinions.

  "All we have to do," Smith said at last, "is get rid of that littlebit of metal beyond the thread in the female socket. But there's noway to get it out. We can't use a chisel because the force would warpthe threads. Besides, we couldn't get a chisel in there."

  "And we don't have a chisel," Captain Al-Amin added. "We don't haveany tools at all."

  "Except," said Jayjay, "an electric hand drill and a quarter-inchbit."

  "Well, sure," said Smith. "But what good will that do us?"

  "If we rigged a belt between the drill's motor and the sleeve of thefemale socket, the sleeve would rotate as if it were on a lathe,wouldn't it?"

  Smith blinked. "Sure. Yeah! Hey!" His face brightened. Then it lookedsad again. "But what good would that do us?"

  "You said that all we have between us and success is a fraction of aninch of metal. If we can remove that fraction of an inch, we'resuccessful."

  "But how can you put a thread into that socket?" Smith asked.

  Jayjay beamed as thoug
h it were his birthday. "We don't have to put athread in there. All we have to do is give the thread on the male plugroom to move in. All we have to do is clear away that metal. So we'lluse the drill motor to turn the sleeve as if it were on a lathe."

  Smith still didn't look enthusiastic. "All right. We have a lathe. Butwhat are we going to use for tools? What are we going to cut