t samples, Jenny? I haven't seen Hendrix
for 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 to
wake him up early, then."

"That's funny. He was worried about the plants yesterday and wanted
Hal to test the water and chemical fertilizer. I looked for him this
morning, 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 feel
my stomach hit my insteps. When anything happens to the plants in a
ship, it isn't funny.

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

That really hit me. They developed the stuff to fight off fungus on
Venus, where one part in a billion did the trick. But it was tricky
stuff; one part in ten-million would destroy the chlorophyll in
plants in about twenty hours, or the hemoglobin in blood in about
fifteen 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 seeming
amusement. Jenny's laugh was right in harmony. I caught the drift, and
tried to look as if we were up to some monkey business as we slipped
out of the room. Nobody seemed suspicious.

Then we made a dash for hydroponics, toward the rear of the ship. We
scrambled into the big chamber together, and stopped. Everything
looked normal among the rows of plant-filled tanks, pipes and
equipment. 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 were
bleached to a pale yellow, like boiled grass, and limp. Nothing would
save them now.

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

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

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

* * * * *

In about ten seconds, I noticed the change. The green began to bleach
bef