On the bulkhead, the creature moved. It wasn’t much, but it was there. Prax zoomed in on it as best he could. One massive clawed hand—clawed but still with four fingers and a thumb—braced it, and the other tore at the bulkhead. The first layer was fabric and insulation and it came off in rubbery strips. Once it was gone, the creature attacked the armored steel underneath. Tiny curls of metal floated in the vacuum beside it, catching the light like little stars. Now why was it doing that? If it was trying to do structural damage, there was any number of better ways. Or maybe it was trying to tunnel through the bulkhead, trying to reach something, following some signal …
The cotton ticking disappeared, resolving into the image of a pale, new root springing from a seed. He felt himself smile. Well, that’s interesting.
“What is, Doc?” Amos asked. Prax realized he must have spoken aloud.
“Um,” Prax said, trying to gather the words that would explain what he’d seen. “It’s trying to move up a radiation gradient. I mean … the version of the protomolecule that was loose on Eros fed off radiation energy, and so I guess it makes sense that this one would too—”
“This one?” Alex asked. “What one?”
“This version. I mean, this one’s obviously been engineered to repress most of the changes. It’s hardly changed the host body at all. There have to be novel constraints on it, but it still seems to need a source of radiation.”
“Why, Doc?” Amos asked. He was trying to be patient. “Why do we think it needs radiation?”
“Oh,” Prax said. “Because we shut down the drive, and so the reactor is running at maintenance level, and now it’s trying to dig through to the core.”
There was a pause, and then Alex said something obscene.
“Okay,” Holden said. “There’s no choice. Alex, you need to get that thing out of here before it gets through the bulkhead. We don’t have time to build a new plan.”
“Captain,” Alex said. “Jim—”
“I’ll be in one second after it’s gone,” Amos said. “If you aren’t there, it’s been an honor serving with you, Cap.”
Prax waved his hands, as if the gesture could get their attention. The movement sent him looping slowly through the operations deck.
“Wait. No. That is the new plan,” he said. “It’s moving up a radiation gradient. It’s like a root heading toward water.”
Naomi had turned to look at him as he spun. She seemed to spin, and Prax’s brain reset to feeling that she was below him, spiraling away. He closed his eyes.
“You’re going to have to walk us through this,” Holden said. “Quickly. How can we control it?”
“Change the gradient,” Prax said. “How long would it take to put together a container with some unshielded radioisotopes?”
“Depends, Doc,” Amos said. “How much do we need?”
“Just more than is leaking through from the reactor right now,” Prax said.
“Bait,” Naomi said, catching hold of him and pulling him to a handhold. “You want to make something that looks like better food and lure that thing out the door with it.”
“I just said that. Didn’t I just say that?” Prax asked.
“Not exactly, no,” Naomi said.
On the screen, the creature was slowly building a cloud of metal shavings. Prax wasn’t sure, because the resolution of the image wasn’t actually all that good, but it seemed like its hand might be changing shape as it dug. He wondered how much the constraints placed on the protomolecule’s expression took damage and healing into account. Regenerative processes were a great opportunity for constraining systems to fail. Cancer was just cell replication gone mad. If it was starting to change, it might not stop.
“Regardless,” Prax said, “I think we should probably hurry.”
The plan was simple enough. Amos would reenter the cargo bay and free the captain as soon as the bay doors had shut behind the intruder. Naomi, in ops, would trigger the doors to close the moment the creature had gone after the radioactive bait. Alex would fire the engines as soon as doing so wouldn’t kill the captain. And the bait—a half-kilo cylinder with a thin case of lead foil to keep it from attracting the beast too early—would be walked out through the main airlock and tossed into the vacuum by the only remaining crewman.
Prax floated in the airlock, bait trap in the thick glove of the environment suit. Regrets and uncertainty flooded through his mind.
“Maybe it would be better if Amos did this part,” Prax said. “I’ve never actually done any extravehicular anything before.”
“Sorry, Doc. I’ve got a ninety-kilo captain to haul,” Amos said.
“Couldn’t we automate this? A lab waldo could—”
“Prax,” Naomi said, and the gentleness of the syllable carried the weight of a thousand get-your-ass-out-theres. Prax checked the seals on his suit one more time. Everything reported good. The suit was much better than the one he’d worn leaving Ganymede. It was twenty-five meters from the personnel airlock near the front of the ship to the cargo bay doors at the extreme aft. He wouldn’t even have to go all the way there. He tested the radio tether to make sure it was clipped tightly into the airlock’s plug.
That was another interesting question. Was the radio-jamming effect a natural output of the monster? Prax tried to imagine how such a thing could be generated biologically. Would the effect end when the monster left the ship? When it was burned up by the exhaust?
“Prax,” Naomi said. “Now is good.”
“All right,” he said. “I’m going out.”
The outer airlock door cycled open. His first impulse was to push out into the darkness the way he would into a large room. His second was to crawl on his hands and knees, keeping as much of his body against the skin of the ship as humanly possible. Prax took the bait in one hand and used the toe rings to lift himself up and out.
The darkness around him was overwhelming. The Rocinante was a raft of metal and paint on an ocean. More than an ocean. The stars wrapped around him in all directions, the nearest ones hundreds of lifetimes away, and then more past those and more past those. The sense of being on a tiny little asteroid or moon looking up at a too-wide sky flipped and he was at the top of the universe, looking down into an abyss without end. It was like a visual illusion flipping between a vase and then two faces, then back again at the speed of perception. Prax grinned up, spreading his arms into the nothingness even as the first taste of nausea crawled up the back of his tongue. He’d read accounts of extravehicular euphoria, but the experience was unlike anything he’d imagined. He was the eye of God, drinking in the light of infinite stars, and he was a speck of dust on a speck of dust, clipped by his mag boots to the body of a ship unthinkably more powerful than himself, and unimportant before the face of the abyss. His suit’s speakers crackled with background radiation from the birth of the universe, and eerie voices whispered in the static.