The details, the sudden distractions and improvisations, piled up and thickened in a way that made Dinah think of a sonic boom on Old Earth: the onrushing stream of air thickening and solidifying in the path of the airplane, turning into a barrier that must be broken through or succumbed to. They seemed to break through it at the point when Michael and two other spacewalkers pulled on their cooling garments, much patched and mended, and donned their space suits. Doob had the incoming heptad on radar, then on optical, and verified that it was on course to rendezvous with them. This meant, of course, that the heptad was on a collision course with Endurance; the difference between a collision and a rendezvous was the final burn of the heptad’s thrusters that would slow it down at the last minute and bring its params into nearly perfect synchronization with the larger ship’s. Endurance herself, still burdened with Amalthea and with many tons of stored propellant, had next to no maneuverability, and so it would all be up to Aïda, or whoever was at the controls of her heptad.
The reunion of Endurance and the Swarm began, as it turned out, with a collision. It was not a catastrophic high-speed collision, but it certainly was no orderly and controlled rendezvous. Aïda had the presence of mind to give them about thirty seconds’ warning. Until then it had all been going well. The heptad had approached, using its thrusters to kill most of its velocity relative to the larger ship, and executed some little burns intended to bring it home to the docking port. Then Aïda announced, in a barely controlled tone of voice, that one of the thruster modules had run out of propellant and could no longer perform its function.
“It’s too heavy,” Zeke muttered. “They loaded in too much cargo; the thrusters are eating too much fuel trying to push all of that crap around.”
The heptad came in too fast and at the wrong angle and crashed into Caboose 2, which was a module, recycled from the wreckage of the Shipyard three years ago, that they had plugged into the back of H1 to serve as the aft-most thing in the Stack. They saw it happen on their screens, they felt it in their bones, and they heard the three spacewalkers exclaiming and cursing. A little storm of debris emerged from a hole that had evidently been torn in the skin of Caboose 2.
“C2 depressurized,” Tekla reported. “Sealed off from Stack.”
The debris cloud included one large object that had two arms, two legs, and a head. The limbs were flailing. Everyone watched silently.
“We lost Michael Park,” one of the other spacewalkers announced.
“We need more people back there,” Ivy announced to the crew in the Hammerhead.
Ivy’s message was clear. Later we will mourn for Michael. Now we have other things to worry about.
“Moira, you stay,” Ivy added.
Moira hadn’t even moved. She was accustomed to being treated, against her own will and instincts, like a cherished and fragile child.
“Maybe you could talk to Michael on the radio. He’ll be alive for a while.”
Moira nodded, swallowed hard, and focused on her laptop, entering the commands needed to establish a private voice link to Michael.
“Dinah, you stay here—run the robots. We are going to have to do some improvising. Bo, go back. Steve too. Luisa, deal with Aïda over voice—for me it’s too much stress and distraction. Stay in the Hammerhead and make that problem go away for me. Doob, stay here. Zeke, go back.”
Ivy looked around. “If I haven’t mentioned your name yet, go back and see what you can do. Doob, you’re the weatherman. Your job is to make announcements about the storm and when it’s going to hit.”
“Half an hour,” Doob said. “But yes. I will do that.”
Moira, headphones on, had retreated into the quietest corner of the Hammerhead and was engaging in a murmured conversation with Michael. She was holding a cloth over her eyes to absorb tears before they broke loose in the cabin. Luisa had already gone into her assigned role and had been listening to a voice transmission from Aïda. “She says she is going to try again.”
“I thought her thrusters were empty,” Ivy said.
“She can transfer propellant from some of the other thruster modules to the empty one. It’ll take a few minutes. She requests instructions on where to make the next attempt, since the docking port on Caboose 2 has been rendered unusable.”
With a bit of deliberation they agreed that the heptad should make its next attempt on a docking port in the old Zvezda module.
Dinah, who had spent most of the last couple of days preparing for the docking to occur on Caboose 2, sent her robots scrambling forward along the outside of the Stack, bringing their cables with them. That caught her up in a stew of minor complications that more than filled the time it took for the heptad to get its dead thruster up and running again.
They watched the second approach, and the docking, in silence. It took about ten minutes. Doob interrupted once to give an update on the approaching radiation storm.
Unexpectedly, it was Moira who broke the silence. “Don’t let them dock,” she said.
“What?!” Ivy said.
“It’s a trap.”
Zeke’s voice came over the PA: “Positive docking achieved. Getting ready to open the hatch.”
Moira added, “Michael figured it out.”
“Fifteen minutes before the storm breaks,” Doob announced.
Dinah had entered into a state of intense focus on the problem to be solved, seeing through the eyes of ten different robots performing ten different tasks, occasionally blurting out terse requests to the two surviving spacewalkers, asking them to shake a stuck cable loose or pull a wriggling Grabb out of trouble. She tried to filter out the conversation between Moira and Ivy.
“What do you mean, it’s a trap?”
“Aïda’s heptad joined the mesh network as soon as it got within range,” Moira said. “If you check your email right now, or your Spacebook, you’ll see stuff flooding into it. Terabytes of old messages and posts that have been bottled up in the Swarm. Mailing list traffic that’s three years old.”
“So?” Ivy asked.
“Michael saw some weird stuff just now, and drew my attention to it.”
“He’s floating in space!”
“He’s floating in space and checking his email.”
“What weird stuff did he notice?”
“They’re cannibals, Ivy.”
“We already know that.”
“A few hours ago,” Moira said, “they slaughtered Tav and ate what was left of him.”
Dinah was having difficulty focusing on her work.
“They wanted to be well fed for today.”
The time was approaching when the spacewalkers would have to go to their airlocks and get indoors ahead of the storm. Dinah had to focus on them. There was nothing she could do about what Moira was saying. She began speaking to one of them but was interrupted when Zeke came over the PA again: “Ten survivors aboard. Waiting for J.B.F. to emerge from the hatch.”
“Zeke, be on your toes,” Ivy said. “We have indications they may be up to no good.”
“Get inside,” Dinah said to the spacewalkers. “Head for the nearest airlock. Stay away from the new people, we don’t trust them.”
“Ditching the rock,” Ivy announced. A sharp hiss came through the walls as compressed air flooded the hair-thin gap between the outer surface of the Hammerhead and the surrounding cavity of Amalthea. “Plug your ears.” Then, before anyone could comply, a shattering, sickening bang as Dinah’s demolition charges went off, destroying the structural connections that joined Amalthea to Endurance. They felt a sharp jostle—more acceleration than they had experienced in three years—as the Hammerhead sprang free, pushing the rest of Endurance along with it.
“Three minutes before the storm hits,” Doob said.
“J.B.F. is aboard,” Luisa announced. She was on voice to Zeke and the rest of the crew aft, relaying what they said to the others in the Hammerhead. Her brow wrinkled. “Something’s wrong with her—I don’t quite follow.”