… The ship, finally completed, standing in three parts on the sand not far from the Library. Phssthpok’s army assembling. We need monopoles, we need tree-of-life roots and seeds, we need enormous quantities of hydrogen fuel. The scoop won’t work below a certain speed. Meteor Bay has everything we need. We can take them! For the first time in twenty thousand years, the childless protectors of Pak assembled for war…

… His own Virus QQ used on breeders, with mopup squads to hunt the survivors. Newly childless protectors switching sides, joining his army. Hratchp reporting in with the strange, complex secret of the tree-of-life root…

Something thumped three times on the hull.

For an instant he thought it was a memory. He was that far gone. Then he was on his feet, staring up at a point high on the curved wall of the hold. His mind racing.

He had known that there was some kind of non-organic photosynthetic process going on on the surface of the dust. Now his mind extrapolated: currents in the dust, photosynthesis going on on the top, currents bringing food down to larger forms of life. He should have guessed before, and checked. He was far gone, was Phssthpok. Age and dwindling motivation were switching him off too early.

Three measured thumps came from almost beneath his feet.

He crossed the hold in one leap, landed softly, silently. Picked up the flat-nosed softener key. Waited.

Hypothesis: something intelligent was sounding the cargo hold for echoes. Size: unknown. Intelligence: unknown. Sophistication: probably low due to their environment. They would be blind down here, if they had eyes at all. A feel for sound could compensate. The echoes from this thumping could tell them a good deal about what was inside. And then?

They would try to break in. Intelligent beings were curious.

Twing was tough, but not invulnerable.

Phssthpok leapt straight upward, through the hatch and into the control cubby. He hated to leave the captive, but there was no choice. He closed the door to the cargo hold, tested it to be sure it was locked. He climbed rapidly into his pressure suit.

Three measured thumps from somewhere below him. Pause.

Something thumped next to his right arm. Phssthpok applied the softener key to the twing. Thump — and a foot of crude glass rod slammed through the twing. Phssthpok yanked hard on it, reached through the wall and had something softer. He pulled.

He had something roughly Pak-shaped, both smaller and denser than a Pak. It was clutching a reversed spear. Phssthpok hit it savagely where its head joined its shoulders. Something broke, and it went limp. Phssthpok probed its body for soft spots. There was a spot in the middle of its body where bone did not protect. Phssthpok pushed hard into it and clutched with his fingers until he felt something give. Presumably it was dead.

It began to smoke.

Phssthpok watched.

Something in the pod’s atmosphere was causing it to give off fumes. That seemed promising. The spear did not speak for a high civilization. Probably they would have nothing that could penetrate twing. He did not like to risk it — but the alternative was to leak his own breathing-air into the surrounding dust, to poison it.

He opened his helmet for a moment and sniffed. Closed it fast. But he’d smelled chemicals he was familiar with…

He got a squeeze of water, trickled it on the alien’s leg. The result was a fireball. Phssthpok leapt away. From across the room he watched the alien burn.

That seemed straightforward enough.

He went to work rigging a hose from the pod’s water supply to the hull. His last moves he made in haste: using the softener key, running the hose through the hull, removing the key to harden the twing, then running water. There was frantic thumping from all over the hull. It stopped rather suddenly.

He ran most of his reserve of water out into the dust.

He waited several hours, until the whine of the air system dropped to normal. Then he doffed his pressure suit and rejoined Brennan. The captive had noticed nothing.

The water should hold off the natives for awhile. But Phssthpok’s reserves were dwindling almost ludicrously. His ship was abandoned, his remaining drive system was useless, his environment bordered by a spherical shell of dust. Now his water reserve was gone. His life story was almost visibly coming to a close.

Presently he dreamed.

The Blue Ox had circled the sun and was now on the other side of the system, headed for interstellar space. Between Ox and U Thant there was a communications gap of thirty minutes. Sohl and Garner waited, knowing that any information would be half-an-hour late.

Mars was three-quarters fall and impressively large in their rear view camera.

They had asked all the questions, made guesses at the answers, mapped out their search pattern of the Lacis Solis region. Luke was bored. He missed the conveniences built into his travel chair. He thought Nick was bored too, but he was wrong. In space Nick was silent by habit.

The screen flashed on: a woman’s face. The radio cleared its throat and spoke.

“U Thant, this is Tina Jordan aboard Blue Ox.” Luke sensed the woman’s barely repressed panic. Tina caught on her own voice, then blurted, “We’re in trouble. We were testing that alien root in the lab and Einar took a bite out of it! The damn thing was like asbestos from vacuum exposure, but he chewed a piece off and swallowed if before we could stop him. I can’t understand why he did it. It smelled awful!

“Einar’s sick, very sick. He tried to kill me when I took the root away from him. Now he’s gone into coma. We’ve hooked him into the ship’s ’doc. The ’doc says Insufficient Data.” They heard a ragged intake of breath. Luke thought he could see bruises beginning to form on the woman’s throat. “We’d like permission to get him to a human doctor.”

Nick cursed and keyed Transmit. “Nick Sohl speaking. Pick a route and get on it. Then finish analyzing that root. Did the smell remind you of anything? Sohl over.” He turned it off. “What the blazes got into him?”

Luke shrugged. “He was hungry?”

“Einar Nilsson, for Finagle’s sake! He was my boss for a year before he quit politics. Why would he try a suicidal trick like that? He’s not stupid.” Nick drummed on the arm of his chair, then began looking for Ceres with the com laser.

In the half hour that passed before the Blue Ox called again, he got dossiers on all three of her crew. “Tina Jordan’s a flatlander. That explains why they waited for orders,” he said.

“Does that need an explanation?”

“Most Belters would have turned around the moment Einar came down sick. The Outsider ship’s empty, and there’s no problem tracking it. No real point in staying. But Jordan’s still a flatlander, still used to being told when to breathe, and La Pan probably didn’t trust his own judgment enough to overide her.”

“Age,” said Luke. “Nilsson was the oldest.”

“What would that have to do with it?”

“I don’t know. He was also the biggest. Maybe he was after a new taste thrill… no, dammit, I don’t believe it either—”

“Blue Ox calling U Thant. We’re on our way home. Course plotted for Vesta. The root analyzes almost normal. High in carbohydrates, including right-hand sugars. The proteins look ordinary. No vitamins at all. We found two compounds Nate says are brand new. One resembles a hormone, testosterone, but it definitely isn’t testosterone.

“The root doesn’t smell like anything I can name, except possibly sour milk or sour cream. The air in the Outsider ship was thin, with an adequate partial pressure of oxygen, no poisonous compounds, at least two percent helium. We spectroanalyzed the porthole material, and—” She listed a spectrum of elements, high in silicone. “The ’doc still reports Einar’s illness as Insufficient Data, but now there’s an emergency light. Whatever it is, it’s not good. Any further questions?”