Markus seemed to have come to the same conclusion. “Jiro?” he asked. “News from the belly of the beast?”

“It’s alive,” Jiro said, in what might have been either awkward phrasing, or a second consecutive joke. “I am trying to make sense of the logs. There is a lot of repetitive material.”

“Error messages?” Markus asked, making the obvious guess.

“Not so much. It is robot stuff. Status reports.”

Dinah moved over one seat and had a look. Though she couldn’t tell exactly what was going on, her general read tallied with Jiro’s. Lots of robots had been working away, executing variations on the same small set of programmed behaviors, pumping out occasional status reports—and, yes, some error messages—that had generated a log too vast for any human to read. They would have to sort it out later by writing a computer script that would crawl through it, accumulating statistics and looking for patterns.

“Could you scroll to the top, please?” she asked. She wanted to know the date and time of the first log entry.

“I checked it,” Jiro said. “Right around the time of Sean’s last transmission.”

So Sean, probably knowing that he was at death’s door, had told the robots to do something, and to keep doing it, until they were ordered to stop. Since the outer surface of the shard was pretty quiet, this probably related to some internal work hidden beneath the surface. “Mining fuel, probably,” Dinah guessed. Then, before Jiro could object to the incorrect choice of words, “Propellant, that is.”

Vyacheslav exposed the docking port. Using a combination of taps on New Caird’s thrusters, some pushing and pulling by the robots, and Vyacheslav simply grabbing the spacecraft and nudging it this way and that, they inserted her “front door” docking port into the little crater that Vyacheslav and the robots had excavated, and mated it with that of Ymir’s buried command module.

Slava then had to reenter New Caird through its side airlock. By sounds conducted through the hull they could track his progress as he climbed into the chamber, closed the outer hatch, and activated the system that would fill the lock with air.

In the meantime, Markus was able to make contact with the computers on the other side of the port, and verify that there was breathable air and other amenities.

It was damned cold, though: about twenty degrees below freezing.

“That was Sean doing us a favor,” Markus said. “He turned the thermostat down before he died. His body will be frozen solid.” For Ymir had no lack of power from its nuclear generators, and its electrical systems were still working.

Markus entered a command that would turn the command module’s environmental systems back on and bring the temperature back up. He pressurized the tiny space between Ymir’s hatch and New Caird’s. Then he opened the latter.

They were all looking now at the slightly domed exterior surface of the hatch that would lead into Ymir’s command module.

Someone had written on it with a felt-tipped marker. He had drawn the trefoil symbol used to warn of radiation hazards and beneath it had written the Greek letters alpha, beta, and gamma. Then, as a darkly humorous doodle, he had added a crude skull and crossbones.

Markus was the first to recover. He spiraled out of the pilot’s chair and propelled himself aft to the inner hatch of the airlock. There he punched a virtual button on a screen, which had the effect of locking the inner hatch. He was not letting Vyacheslav come in. He reached up with one hand and adjusted his headset. “Slava,” he said, “can you hear me? Good. Listen. We have contamination. You may have picked some of it up on your space suit. Before you come inside, I would like you to go over to Jiro’s external radiation detector and see if we pick anything up.”

Jiro was already scanning the hatch with his Eenspektor, fortunately without results.

Outside they could hear Vyacheslav cycling the airlock again and clambering back out. Using external handholds on the hull he made his way to the place where the external gamma spec was mounted, and devoted a couple of minutes to turning this way and that, directly in front of them, paying particular attention to his gloves, his knees, his boots—anything that had come into contact with the ice. No bursts of radiation were noticed, and so he was given clearance to go back to the airlock and enter New Caird.

They had brought warm clothes, which seemed advisable when going on a journey to a huge piece of ice. Jiro put his on. Dinah reached for the stuff sack in which she had stored hers, but Markus held up a restraining hand. She noticed he was making no effort to dress for the occasion. Jiro was going down there alone.

“I am going to overpressurize us a little bit,” Markus said, working with an interface on his pad. Dinah felt pressure building against her eardrums. Markus didn’t explain himself, and didn’t have to: they wanted clean air from New Caird to waft into Ymir, as opposed to potentially contaminated air coming in here.

Jiro then pulled a disposable one-piece bunny suit over his cold-weather gear. For they had come prepared to find the ship contaminated. He slung his Eenspektor over the outside of the bunny suit. Dinah handed him a respirator mask, so that he wouldn’t breathe radioactive dust into his lungs, and he pulled it on over the bunny suit’s hood and checked it for a good seal against his face. He pivoted into the space between the ships, operated the external latch on Ymir’s hatch, and jerked forward slightly as the overpressure in New Caird pushed it open. He let himself drift into the command module, then got himself turned around so that his feet were oriented toward the “floor.” Meanwhile Markus pulled the hatch closed behind him.

Vyacheslav by now had emerged from the airlock. He, Dinah, and Markus were listening to Jiro’s breathing on their headsets.

“Sean bled to death,” Jiro announced.

YMIR’S COMMAND MODULE WAS ARKLET-SIZED. OF COURSE, THAT went for almost everything now in space, since an arklet was just the biggest object that could be launched into orbit on the top of a heavy-lift booster. Some arklets were “tunnel,” meaning that they were laid out in a “horizontal” orientation, meant to lie flat, as it were, like railroad tank cars, with a single long floor running from end to end. This was good if you wanted a large open space, but tended to be a less efficient use of available volume. The command module of Ymir, like that of New Caird, was “silo,” meaning that it was oriented in a “vertical” way, diced into a number of round stories—typically four or five—joined by a ladder. Each story was a fat disk of space about four meters in diameter, big enough for one room that would be considered large by space travel standards, but more often divided into smaller compartments.

Ymir was a five-story silo, meaning that it had low ceilings that must have made it a claustrophobic place in which to spend a two-year journey. The first story Jiro had entered, being closest to the surface with its cosmic ray and bolide hazards, was a single room. On the plans, it was supposed to be used for storage of things like food, scrubber cartridges, robot parts, and tools.

After a few minutes Jiro was able to set up a video link from a camera mounted to his head. They watched it on their tablets.

The frozen body of Sean Probst was floating in a sleep sack that had been zip-tied to the ceiling. The porous fabric was stained dark brown. Very little of it had not been soaked with blood.

Bumping lightly against him was an old-school Geiger counter, tethered by another zip tie. The word BUSTED had been written on it with the same felt-tip pen used to make the sign.