thing, butour artificial gravity is darned near foolproof.

  It was ten years since I'd moved in free fall, but Space Tech had donea good job of training good habits. I got out of my bunk, hit thecorridor with a hand out, bounced, kicked, and dove toward the messhall without a falter. The crewmen weren't doing so well--but theywere coming up the corridor fast enough.

  I could have wrung Muller's neck. Normally, in case of trouble,cutting gravity is smart. But not here, where the crew already wanteda chance to commit mayhem, and had more experience than thescientists.

  Yet, surprisingly, when I hit the mess hall ten feet ahead of thedeckhands, most of the scientists were doing all right. Hell, I shouldhave known Pietro, Sanderson and a couple others would be used tono-grav; in astronomical work, you cut your eye teeth on that. Theywere braced around the cook, who huddled back in a corner, while ourpurser-steward, Sam, was still singing for help.

  The fat face of the cook was dead white. Bill Sanderson, looking likea slim, blond ballet dancer and muscled like an apache expert, had himin one hand and was stuffing the latest batch of whole wheat biscuitsdown his throat. Bill's sister, Jenny, was giggling excitedly andholding more biscuits.

  The deckhands and Grundy, the mate, were almost at the door, and I hadjust time enough to slam it shut and lock it in their faces. I meantto enjoy seeing the cook taken down without any interruption.

  Sam let out a final yell, and Bullard broke free, making a mess of itwithout weight. He was sputtering out bits of the biscuit. Hal Lomaxreached out a big hand, stained with the chemicals that had been hislife's work, and pushed the cook back.

  And suddenly fat little Bullard switched from quaking fear to a blindrage. The last of the biscuit sailed from his mouth and he spat atHal. "You damned hi-faluting black devil. You--_you_ sneering at mycooking. I'm a white man, I am--I don't have to work for no blackni...."

  * * * * *

  I reached him first, though even Sam started for him then. You candeliver a good blow in free-fall, if you know how. His teeth againstmy knuckles stopped my leap, and the back of his head bounced off thewall. He was unconscious as he drifted by us, moving upwards. Myknuckles stung, but it had been worth it. Anyhow, Jenny's look morethan paid for the trouble.

  The door shattered then, and the big hulk of Mate Grundy tumbled in,with the two deckhands and the pair from the engine room behind him.Sam let out a yell that sounded like protest, and they headed forus--just as gravity came on.

  I pulled myself off the floor and out from under Bullard to see thestout, oldish figure of Captain Muller standing in the doorway, withEngineer Wilcox slouched easily beside him, looking like the typicalnatty space officer you see on television. Both held gas guns.

  "All right, break it up!" Muller ordered. "You men get back to yourwork. And you, Dr. Pietro--my contract calls for me to deliver you toSaturn's moon, but it doesn't forbid me to haul you the rest of theway in irons. I won't have this aboard my ship!"

  Pietro nodded, his little gray goatee bobbing, his lean body comingupright smoothly. "Quite right, Captain. Nor does it forbid me to letyou and your men spend the sixteen months on the moon--where _I_command--in irons. Why don't you ask Sam what happened before you makea complete fool of yourself, Captain Muller?"

  Sam gulped and looked at the crew, but apparently Pietro was right;the little guy had been completely disgusted by Bullard. He shruggedapologetically. "Bullard insulted Dr. Lomax, sir. I yelled for someoneto help me get him out of here, and I guess everybody got all mixed upwhen gravity went off, and Bullard cracked his head on the floor. Justa misunderstanding, sir."

  Muller stood there, glowering at the cut on my knuckles, and I couldfeel him aching for a good excuse to make his threat a reality. Butfinally, he grunted and swung on his heel, ordering the crew with him.Grundy threw us a final grimace and skulked off behind him. Finallythere was only Wilcox, who grinned, shrugged, and shut the doorquietly behind him. And we were left with the mess free-fall had madeof the place.

  I spotted Jenny heading across the room, carefully not seeing thefatuous glances Pietro was throwing her way, and I swung in behind.She nodded back at me, but headed straight for Lomax, with an odd lookon her face. When she reached him, her voice was low and businesslike.

  "Hal, what did those samples of Hendrix's show up?"

  Hendrix was the Farmer, in charge of the hydroponics that turned thecarbon dioxide we breathed out back to oxygen, and also gave us a bitof fresh vegetables now and then. Technically, he was a crewman, justas I was a scientist; but actually, he felt more like one of us.

  Lomax looked surprised. "What samples, Jenny? I haven't seen Hendrixfor two weeks."

  "You--" She stopped, bit her lip, and frowned. She swung on me. "Paul,have you seen him?"

  I shook my head. "Not since last night. He was asking Eve and Walt towake him up early, then."

  "That's funny. He was worried about the plants yesterday and wantedHal to test the water and chemical fertilizer. I looked for him thismorning, but when he didn't show up, I thought he was with you, Hal.And--the plants are dying!"

  "All of them?" The half smile wiped off Hal's face, and I could feelmy stomach hit my insteps. When anything happens to the plants in aship, it isn't funny.

  She shook her head again. "No--about a quarter of them. I was comingfor help when the fight started. They're all bleached out. And itlooks like--like chromazone!"

  That really hit me. They developed the stuff to fight off fungus onVenus, where one part in a billion did the trick. But it was trickystuff; one part in ten-million would destroy the chlorophyll inplants in about twenty hours, or the hemoglobin in blood in aboutfifteen minutes. It was practically a universal poison.

  Hal started for the door, then stopped. He glanced around the room,turned back to me, and suddenly let out a healthy bellow of seemingamusement. Jenny's laugh was right in harmony. I caught the drift, andtried to look as if we were up to some monkey business as we slippedout of the room. Nobody seemed suspicious.

  Then we made a dash for hydroponics, toward the rear of the ship. Wescrambled into the big chamber together, and stopped. Everythinglooked normal among the rows of plant-filled tanks, pipes andequipment. Jenny led us down one of the rows and around a bend.

  The plants in the rear quarter weren't sick--they were dead. They werebleached to a pale yellow, like boiled grass, and limp. Nothing wouldsave them now.

  "I'm a biologist, not a botanist--" Jenny began.

  Hal grunted sickly. "Yeah. And I'm not a life hormone expert. Butthere's one test we can try."

  He picked up a pair of rubber gloves from a rack, and pulled off somewilted stalks. From one of the healthy tanks, he took green leaves. Hemashed the two kinds together on the edge of a bench and watched. "Ifit's chromazone, they've developed an enzyme by now that should eatthe color out of those others."

  * * * * *

  In about ten seconds, I noticed the change. The green began to bleachbefore my eyes.

  Jenny made a sick sound in her throat and stared at the rows ofhealthy plants. "I checked the valves, and this sick section isisolated. But--if chromazone got into the chemicals.... Better get yourspectroanalyzer out, Hal, while I get Captain Muller. Paul, be a dearand find Hendrix, will you?"

  I shook my head, and went further down the rows. "No need, Jenny," Icalled back. I pointed to the shoe I'd seen sticking out from the edgeof one of the tanks. There was a leg attached.

  I reached for it, but Lomax shoved me back. "Don't--the enzymes in thecorpse are worse than the poison, Paul. Hands off." He reached downwith the gloves and heaved. It was Hendrix, all right--a corpse with aface and hands as white as human flesh could ever get. Even the lipswere bleached out.

  Jenny moaned. "The fool! The stupid fool. He _knew_ it was dangerouswithout gloves; he suspected chromazone, even though none's supposedto be on board. And I warned him . . ."

  "Not against this, you didn't," I told her. I dropped to my knees
andtook another pair of gloves. Hendrix's head rolled under my grasp. Theskull was smashed over the left eye, as if someone had taken asideswipe at Hendrix with a hammer. No fall had produced that. "Youshould have warned him about his friends. Must have been killed, thendumped in there."

  "Murder!" Hal bit the word out in disgust. "You're right, Paul. Nottoo stupid a way to dispose of the body, either--in another couple ofhours, he'd have started dissolving in that stuff, and we'd never haveguessed it was murder. That means this poisoning of the plants wasn'tan accident. Somebody poisoned the water, then got worried when therewasn't a report on the plants; must have been someone who thought itworked faster on plants than it does. So he came to investigate, andHendrix caught him fooling