know but maybe he was gonna dump the fuel? And then I seen hehad keys. I didn't wait, sir. I jumped him. And then you come up."

  Wilcox came from the background and dropped beside the still figure ofLomax. He opened the man's left hand and pulled out a bunch of keys,examining them. "Engine keys, Captain Muller. Hey--it's my set! Hemust have lifted them from my pocket. It looks as if Grundy's foundour killer!"

  "Or Lomax found him!" I pointed out. "Anybody else see this start, orknow that Lomax didn't get those keys away from Grundy, when _he_started trouble?"

  "Why, you--" Grundy began, but Wilcox cut off his run. It was a shame.I still felt like pushing the man's Adam's apple through his medullaoblongata.

  "Lock them both up, until Dr. Lomax comes to," Muller ordered. "Andsend Dr. Napier to take care of him. I'm not jumping to anyconclusions." But the look he was giving Lomax indicated that he'dalready pretty well made up his mind. And the crew was positive. Theydrew back sullenly, staring at us like animals studying a humanhunter, and they didn't like it when Peters took Grundy to lock himinto his room. Muller finally chased them out, and left Wilcox and mealone.

  Wilcox shrugged wryly, brushing dirt off his too-clean uniform. "Whileyou're here, Tremaine, why not look my section over? You've beenneglecting me."

  I'd borrowed Muller's keys and inspected the engine room from, top tobottom the night before, but I didn't mention that. I hesitated now;to a man who grew up to be an engineer and who'd now gotten over hispsychosis against space too late to start over, the engines werethings better left alone. Then I remembered that I hadn't seenWilcox's quarters, since he had the only key to them.

  I nodded and went inside. The engines were old, and the gravitygenerator was one of the first models. But Wilcox knew his business.The place was slick enough, and there was the good clean smell ofmetal working right. I could feel the controls in my hands, and mynerves itched as I went about making a perfunctory token examination.I even opened the fuel lockers and glanced in. The two crewmen watchedwith hard eyes, slitted as tight as Grundy's, but they didn't botherme. Then I shrugged, and went back with Wilcox to his tiny cabin.

  * * * * *

  I was hit by the place before I got inside. Tiny, yes, but fixed uplike the dream of every engineer. Clean, neat, filled with books andluxuries. He even had a tape player I'd seen on sale for a trifle overthree thousand dollars. He turned it on, letting the opening bars ofHaydn's Oxford Symphony come out. It was a binaural, ultra-fidelityjob, and I could close my eyes and feel the orchestra in front of me.

  This time I was thorough, right down the line, from the cabinets thatheld luxury food and wine to the little drawer where he kept hisdress-suit studs; they might have been rutiles, but I had a hunch theywere genuine catseyes.

  He laughed when I finished, and handed me a glass of the first decent wineI'd tasted in months. "Even a small ozonator to make the air seem morebreathable, and a dehumidifier, Tremaine. I like to live decently. Istarted saving my money once with the idea of getting a ship of my own--"There was a real dream in his eyes for a second. Then he shrugged. "Butships got bigger and more expensive. So I decided to live. At forty, I'vegot maybe twenty years ahead here, and I mean to enjoy it. And--well,there are ways of making a bit extra...."

  I nodded. So it's officially smuggling to carry a four-ounce Martianfur to Earth where it's worth a fortune, considering the legal duty.But most officers did it now and then. He put on Sibelius' Fourthwhile I finished the wine. "If this mess is ever over, Paul, or youget a chance, drop down," he said. "I like a man who knows goodthings--and I liked your reaction when you spotted that Haydn forHohmann's recording. Muller pretends to know music, but he likes theflashiness of Mohlwehr."

  Hell, I'd cut my eye teeth on that stuff; my father had been firstviolinist in an orchestra, and had considered me a traitor when I wasborn without perfect pitch. We talked about Sibelius for awhile,before I left to go out into the stinking rest of the ship. Grundy wassitting before the engines, staring at them. Wilcox had said the bigape liked to watch them move ... but he was supposed to be locked up.

  * * * * *

  I stopped by Lomax's door; the shutter was open, and I could see thebig man writhing about, but he was apparently unconscious. Napier cameback from somewhere, and nodded quickly.

  "Concussion," he said. "He's still out, but it shouldn't be tooserious."

  "Grundy's loose." I'd expected surprise, but there was none. "Why?"

  He shrugged. "Muller claimed he needed his mate free to handle thecrew, and that there was no place the man could go. I think it wasbecause the men are afraid they'll be outnumbered by your group." Hismouth smiled, but it was suddenly bitter. "Jenny talked Pietro intoagreeing with Muller."

  Mess was on when I reached the group. I wasn't hungry. The wine hadcut the edge from my appetite, and the slow increase of poison in theair was getting me, as it was the others. Sure, carbon dioxide isn't areal poison--but no organism can live in its own waste, all the same.I had a rotten headache. I sat there playing a little game I'dinvented--trying to figure which ones I'd eliminate if some had todie. Jenny laughed up at Muller, and I added him to the list. Then Ichanged it, and put her in his place. I was getting sick of the littlewitch, though I knew it would be different if she'd been laughing upat me. And then, because of the sick-calf look on Bill Sanderson'sface as he stared at Eve, I added him, though I'd always liked theguy. Eve, surprisingly, had as many guys after her as Jenny; but shedidn't seem interested. Or maybe she did--she'd pulled her hair backand put on a dress that made her figure look good. Either flattery wasworking, or she was entering into the last-days feeling most of ushad.

  Napier came in and touched my shoulder. "Lomax is conscious, and he'sasking for you," he said, too low for the others to hear.

  I found the chemist conscious, all right, but sick--and scared. Hisface winced, under all the bandages, as I opened the door. Then he sawwho it was, and relaxed. "Paul--what happened to me? The last Iremember is going up to see that second batch of plants poisoned.But--well, this is something I must have got later...."

  I told him, as best I could. "But don't you remember anything?"

  "Not a thing about that. It's the same as Napier told me, and I'vebeen trying to remember. Paul, you don't think--?"

  I put a hand on his shoulder and pushed him back gently. "Don't be adamned fool, Hal. I know you're no killer."

  "But somebody is, Paul. Somebody tried to kill me while I wasunconscious!"

  He must have seen my reaction. "They did, Paul. I don't know how Iknow--maybe I almost came to--but somebody tried to poke a stickthrough the door with a knife on it. They want to kill me."

  I tried to calm him down until Napier came and gave him a sedative.The doctor seemed as sick about Hal's inability to remember as I was,though he indicated it was normal enough in concussion cases. "So isthe hallucination," he added. "He'll be all right tomorrow."

  In that, Napier was wrong. When the doctor looked in on him the nexttime, the big chemist lay behind a door that had been pried open, witha long galley knife through his heart. On the bloody sheet, his fingerhad traced something in his own blood.

  "_It was_...." But the last "s" was blurred, and there was nothingmore.

  IV

  I don't know how many were shocked at Hal's death, or how many lookedaround and counted one less pair of lungs. He'd never been one of themen I'd envied the air he used, though, and I think most felt thesame. For awhile, we didn't even notice that the air was even thicker.

  Phil Riggs broke the silence following our inspection of Lomax'scabin. "That damned Bullard! I'll get him, I'll get him as sure as hegot Hal!"

  There was a rustle among the others, and a suddenly crystallized hateon their faces. But Muller's hoarse shout cut through the babble thatbegan, and rose over even the anguished shrieking of the cook. "Shutup, the lot of you! Bullard couldn't have committed the other crimes.Any one of you is a better suspect. Stop snivelling, Bu
llard, thisisn't a lynching mob, and it isn't going to be one!"

  "What about Grundy?" Walt Harris yelled.

  Wilcox pushed forward. "Grundy couldn't have done it. He's the logicalsuspect, but he was playing rummy with my men."

  The two engine men nodded agreement, and we began filing back to themess hall, with the exception of Bullard, who shoved back into aniche, trying to avoid us. Then, when we were almost out of his sight,he let out a shriek and came blubbering after us.

  I watched them put Hal Lomax's body through the 'tween-hulls lock, andturned toward the engine room; I could use some of that wine, just asthe ship could have used a trained detective. But the idea of watchinghelplessly while the engines purred along to remind me I was just ahandyman for the rest of my life got mixed up with the difficulty ofbreathing the stale air, and I started to turn back. My head wasthrobbing, and for two cents I'd have gone out between the hullsbeside Lomax and the others and let the foul air spread out there andfreeze....

  The idea was slow coming. Then I was running back toward the engines.I caught up with Wilcox just before he went into his own quarters."Wilcox!"

  He swung around casually, saw it was me, and motioned inside. "Howabout some Bartok, Paul? Or would you rather soothe your nerves withsome first-rate Buxtehude organ...."

  "Damn the music," I told him. "I've got a wild idea to get rid of thiscarbon dioxide, and I want to know if we can get it working with whatwe've got."

  He snapped to attention at that. Half-way through my account, hefished around and found a bottle of Armagnac. "I get it. If we pipeour air through the passages between the hulls on the shadow side, itwill lose its heat in a hurry. And we can regulate its finaltemperature by how fast we pipe it through--just keep it moving enoughto reach the level where carbon dioxide freezes out, but the oxygenstays a gas. Then pass it around the engines--we'll have to cut outthe normal cooling set-up, but that's okay--warm it up.... Sure, I'vegot equipment enough for that. We can set it up in a day. Of course,it won't give us any more oxygen, but we'll be able to breathe what wehave. To success, Paul!"

  I guess it was good brandy, but I swallowed mine while calling Mullerdown, and never got to taste it.

  It's surprising how much easier the air got to breathe after we'ddouble-checked the idea. In about fifteen minutes, we were all millingaround in the engine room, while Wilcox checked through equipment. Butthere was no question about it. It was even easier than we'd thought.We could simply bypass the cooling unit, letting the engine housingsstay open to the between-hulls section; then it was simply a matter ofcutting a small opening into that section at the other end of the shipand installing a sliding section to regulate the amount of air flowingin. The exhaust from the engine heat pumps was reversed, and run outthrough a hole hastily knocked in the side of the wall.

  Naturally, we let it flow too fast at first. Space is a vacuum, whichmeans it's a good insulator. We had to cut the air down to a trickle.Then Wilcox ran into trouble because his engines wouldn't cool withthat amount of air. He went back to supervise a patched-up job ofsplitting the coolers into sections, which took time. But after that,we had it.

  I went through the hatch with Muller and Pietro. With air there therewas no need to wear space suits, but it was so cold that we could takeit for only a minute or so. That was long enough to see a faint, finemist of dry ice snow falling. It was also long enough to catch a sightof the three bodies there. I didn't enjoy that, and Pietro gasped.Muller grimaced. When we came back, he sent Grundy in to move thebodies to a hull-section where our breathing air wouldn't pass overthem. It wasn't necessary, of course. But somehow, it seemedimportant.

  By lunch, the air seemed normal. We shipped only pure oxygen at aboutthree pounds pressure, instead of loading it with a lot of uselessnitrogen. With the carbon dioxide cut back to normal levels, it was asgood as ever. The only difference was that the fans had to be set toblow in a different pattern. We celebrated, and even Bullard seemed tohave perked up. He dug out pork chops and almost succeeded in makingus cornbread out of some coarse flour I saw him pouring out of thefood chopper. He had perked up enough to bewail the fact that all hehad was canned spinach instead of turnip greens.

  But by night, the temper had changed--and the food indicated it again.Bullard's cooking was turning into a barometer of the psychicpressure. We'd had time to realize that we weren't getting somethingfor nothing. Every molecule of carbon-dioxide that crystallized outtook two atoms of oxygen with it, completely out of circulation.

  * * * * *

  We were also losing water-vapor, we found; normally, any one of ourgroup knew enough science to know that the water would fall out beforethe carbon dioxide, but we hadn't thought of it. We took care of that,however, by having Wilcox weld in a baffle and keep the section wherethe water condensed separate from the carbon dioxide snowfall. Wecould always shovel out the real ice, and meantime the ship's controlsrestored the moisture to the air easily enough.

  But there was nothing we could do about the oxygen. When that wasgone, it stayed gone. The plants still took care of about two-thirdsof our waste--but the other third was locked out there between thehulls. Given plants enough, we could have thawed it and let themreconvert it; a nice idea, except that we had to wait three months totake care of it, if we lived that long.

  Bullard's cooking began to get worse. Then suddenly, we got one goodmeal. Eve Nolan came down the passage to announce that Bullard wasmaking cake, with frosting, canned huckleberry pie, and all the works.We headed for the mess hall, fast.

  It was the cook's masterpiece. Muller came down late, though, andregarded it doubtfully. "There's something funny," he said as hesettled down beside me. Jenny had been surrounded by Napier andPietro. "Bullard came up babbling a few minutes ago. I don't like it.Something about eating hearty, because he'd saved us all, forever andever. He told me the angels were on our side, because a beautifulangel with two halos came to him in his sleep and told him how to saveus. I chased him back to the galley, but I don't like it."

  Most of them had already eaten at least half of the food, but I sawMuller wasn't touching his. The rest stopped now, as the words sankin, and Napier looked shocked. "No!" he said, but his tone wasn'tpositive. "He's a weakling, but I don't think he's insane--not enoughto poison us."

  "There was that food poisoning before," Pietro said suddenly. "Paul,come along. And don't eat anything until we come back."

  We broke the record getting to the galley. There Bullard sat, beaminghappily, eating from a huge plate piled with the food he had cooked. Ichecked on it quickly--and there wasn't anything he'd left out. Helooked up, and his grin widened foolishly.

  "Hi, docs," he said. "Yes, sir, I knowed you'd be coming. It all cameto me in a dream. Looked just like my wife twenty years ago, she did,with green and yellow halos. And she told it to me. Told me I'd been agood man, and nothing was going to happen to me. Not to good old EmeryBullard. Had it all figgered out."

  He speared a big forkful of food and crammed it into his mouth,munching noisily. "Had it all figgered. Pop-corn. Best damned pop-cornyou ever saw, kind they raise not fifty miles from where I was born.You know, I didn't useta like you guys. But now I love everybody. Whenwe get to Saturn, I'm gonna make up for all the times I didn't giveyou pop-corn. We'll pop and we'll pop. And beans, too. I useta hatebeans. Always beans on a ship. But now we're saved, and I lovebeans!"

  He stared after us, half coming out of his seat. "Hey, docs, ain't yougonna let me tell you about it?"

  "Later, Bullard," Pietro called back. "Something just came up. We wantto hear all about it."

  * * * * *

  Inside the mess hall, he shrugged. "He's eating the food himself. Ifhe's crazy, he's in a happy stage of it. I'm sure he isn't trying topoison us." He sat down and began eating, without any hesitation.

  I didn't feel as sure, and suspected he didn't. But it was too late toback out. Together, we summarized what he'd told us, while Napierpuzzled
over it. Finally the doctor shrugged. "Visions. Euphoria.Disconnection with reality. Apparently something of a delusion thathe's to save the world. I'm not a psychiatrist, but it sounds likeinsanity to me. Probably not dangerous. At least, while he wants tosave us, we won't have to worry about the food. Still...."

  Wilcox mulled it over, and resumed the eating he had neglected before.

  "Grundy claimed he'd been down near the engine room, trying to getpermission to pop something in the big pile. I thought Grundy was justgetting his stories mixed up. But--pop-corn!"

  "I'll have him locked in his cabin," Muller decided. He picked up thenearest handset, saw that it was to the galley, and switched quickly."Grundy, lock Bullard up. And no rough stuff this time." Then heturned to Napier. "Dr. Napier, you'll have to see him and find outwhat you can."

  I guess there's a primitive fear of insanity in most of us. We feltsick, beyond the nagging worry about the food. Napier got up at once."I'll give him a sedative. Maybe it's just nerves, and he'll snap outof it after a good sleep.