Gunther was too distant to hear the CMP's reaction, but he saw both women laugh.  "Well," said Ekatarina.  "At the very least we will have to renegotiate terms with the parent corporations.  With only one ship functional, people can't be easily replaced.  Physical presence has become a valuable commodity.  We'd be fools not to take advantage of it."

He passed on, deeper into shadow, wandering aimlessly.  Eventually, there was a light ahead, and he heard voices.  One was Krishna's, but spoken faster and more forcefully than he was used to hearing it.  Curious, he stopped just outside the door.

Krishna was in the center of the lab.  Before him, Beth Hamilton stood nodding humbly.  "Yes, sir," she said.  "I'll do that.  Yes."  Dumbfounded, Gunther realized that Krishna was giving her orders.

Krishna glanced up.  "Weil!  You're just the man I was about to come looking for."

"I am?"

"Come in here, don't dawdle."  Krishna smiled and beckoned, and Gunther had no choice but to obey.  He looked like a young god now.  The force of his spirit danced in his eyes like fire.  It was strange that Gunther had never noticed before how tall he was.  "Tell me where Sally Chang is."

"I don't--I mean, I can't, I--"  He stopped and swallowed.  "I think Chang must be dead."  Then, "Krishna?  What's happened to you?"

"He's finished his research," Beth said.

"I rewrote my personality from top to bottom," Krishna said.  "I'm not half-crippled with shyness anymore--have you noticed?"  He put a hand on Gunther's shoulder, and it was reassuring, warm, comforting.  "Gunther, I won't tell you what it took to scrape together enough messenger engines from traces of old experiments to try this out on myself.  But it works.  We've got a treatment that among other things will serve as a universal cure for everyone in Bootstrap.  But to do that, we need the messenger engines, and they're not here.  Now tell me why you think Sally Chang is dead."

"Well, uh, I've been searching for her for four days.  And the CMP has been looking too.  You've been holed up here all that time, so maybe you don't know the flicks as well as the rest of us do.  But they're not very big on planning.  The likelihood one of them could actively evade detection that long is practically zilch.  The only thing I can think is that somehow she made it to the surface before the effects hit her, got into a truck and told it to drive as far as her oxygen would take her."

Krishna shook his head and said, "No.  It is simply not consistent with Sally Chang's character.  With all the best will in the world, I cannot picture her killing herself."  He slid open a drawer:  row upon row of gleaming canisters.  "This may help.  Do you remember when I said there were two canisters of mimetic engines missing, not just the schizomimetic?"

"Vaguely."

"I've been too busy to worry about it, but wasn't that odd?  Why would Chang have taken a canister and not used it?"

"What was in the second canister?" Hamilton asked.

"Paranoia," Krishna said.  "Or rather a good enough chemical analog.  Now, paranoia is a rare disability, but a fascinating one.  It's characterized by an elaborate but internally consistent delusional system.  The paranoid patient functions well intellectually, and is less fragmented than a schizophrenic.  Her emotional and social responses are closer to normal.  She's capable of concerted effort.  In a time of turmoil, it's quite possible that a paranoid individual could elude our detection."

"Okay, let's get this straight," Hamilton said.  "War breaks out on Earth.  Chang gets her orders, keys in the sofware bombs, and goes to Bootstrap with a canister full of madness and a little syringe of paranoia--no, it doesn't work.  It all falls apart."

"How so?"

"Paranoia wouldn't inoculate her against schizophrenia.  How does she protect herself from her own aerosols?"

Gunther stood transfixed.  "Lavender!"

They caught up with Sally Chang on the topmost terrace of Bootstrap.  The top level was undeveloped.  Someday--so the corporate brochures promised --fallow deer would graze at the edge of limpid pools, and otters frolic in the streams.  But the soil hadn't been built up yet, the worms brought in or the bacteria seeded.  There were only sand, machines, and a few unhappy opportunistic weeds.

Chang's camp was to one side of a streamhead, beneath a fill light.  She started to her feet at their approach, glanced quickly to the side and decided to brazen it out.

A sign reading EMERGENCY CANOPY MAINTENANCE STATION had been welded to a strut supporting the stream's valve stem.  Under it were a short stacked pyramid of oxytanks and an aluminum storage crate the size of a coffin.   "Very clever," Beth muttered over Gunther's trance chip.  "She sleeps in the storage crate, and anybody stumbling across her thinks it's just spare equipment."

The lavender suit raised an arm and casually said, "Hiya, guys.  How can I help you?"

Krishna strode forward and took her hands.  "Sally, it's me--Krishna!"

"Oh, thank God!"  She slumped in his arms.  "I've been so afraid."

"You're all right now."

"I thought you were an Invader at first, when I saw you coming up.  I'm so hungry--I haven't eaten since I don't know when."  She clutched at the sleeve of Krishna's suit.  "You do know about the Invaders, don't you?"

"Maybe you'd better bring me up to date."

They began walking toward the stairs.  Krishna gestured quietly to Gunther and then toward Chang's worksuit harness.  A canister the size of a hip flask hung there.  Gunther reached over and plucked it off.  The messenger engines!  He held them in his hand.

To the other side, Beth Hamilton plucked up the near-full cylinder of paranoia-inducing engines and made it disappear.

Sally Chang, deep in the explication of her reasonings, did not notice.  "... obeyed my orders, of course.  But they made no sense.  I worried and worried about that until finally I realized what was really going on.  A wolf caught in a trap will gnaw off its leg to get free.  I began to look for the wolf.  What kind of enemy justified such extreme actions?  Certainly nothing human."

"Sally," Krishna said, "I want you to entertain the notion that the conspiracy--for want of a better word--may be more deeply rooted than you suspect.  That the problem is not an external enemy, but the workings of our own brains.  Specifically that the Invaders are an artifact of the psychotomimetics you injected into yourself back when this all began."

"No.  No, there's too much evidence.  It all fits together!  The Invaders needed a way to disguise themselves both physically, which was accomplished by the vacuum suits, and psychologically, which was achieved by the general madness.  Thus, they can move undetected among us.  Would a human enemy have converted all of Bootstrap to slave labor?  Unthinkable!  They can read our minds like a book.  If we hadn't protected ourselves with the schizomimetics, they'd be able to extract all our knowledge, all our military research secrets ..."

Listening, Gunther couldn't help imagining what Liza Nagenda would say to all of this wild talk.  At the thought of her, his jaw clenched.  Just like one of Chang's machines, he realized, and couldn't help being amused at his own expense.

Ekatarina was waiting at the bottom of the stairs.  Her hands trembled noticeably, and there was a slight quaver in her voice when she said, "What's all this the CMP tells me about messenger engines?  Krishna's supposed to have come up with a cure of some kind?"

"We've got them," Gunther said quietly, happily.  He held up the canister.  "It's over now, we can heal our friends."

"Let me see," Ekatarina said.  She took the canister from his hand.

"No, wait!" Hamilton cried, too late.  Behind her, Krishna was arguing with Sally Chang about her interpetations of recent happenings.  Neither had noticed yet that those in front had stopped.