Tom felt himself growing very still. So that’s what it was. That’s why Blackburn had kept him alive in Antarctica. That’s why he’d been so fascinated, learning what Tom could do in the Census Chamber. He saw what Tom could do as something he could use. He saw Tom as a weapon. His heart began to thump so hard, he was sure they could both hear it.

“You can’t do anything to me,” Heather said. “Even if you killed me right now, you’d leave forensic evidence everywhere, and you’d never be able to hide my body in time. You’re bluffing.”

In the darkness beyond, the silvery vactrain had risen up from the tube below, and the chamber was repressurizing. Heather’s ride had arrived.

Tom felt a sense of unreality, realizing that the rest of his life would probably hinge on what happened here between these two people.

“Heather,” Blackburn said, as the doors slid open. “Last chance. Please come with me.”

“Good-bye, sir,” Heather said with a delicate wave. “I’d say it was nice knowing you, but I think I own you now, so we’re not through by a long shot. Count on that.” And then she backed through the doors.

Tom crept forward and saw her whirl around and dash toward the metallic train car waiting for her in the dark chamber.

Blackburn gave a weary sigh, looking ten years older, then he tapped at his forearm keyboard. “Stupid girl.”

A mechanized voice boomed in the air: “Decompression sequence initiated.”

The words didn’t register in Tom’s brain for a moment. All he was aware of was the massive, chugging sound filling the air, and Heather, nearly at the train but not close enough to find shelter inside. She spun back around with naked fear blazing on her face, realizing what was about to happen, realizing now the meaning of Blackburn’s words:

If you try and walk out that door, you’ll be making a deadly mistake. . . .

The metallic vactrain plunged out of sight as the transition chamber depressurized, and a powerful gust of wind blew Heather down into the magnetized vacuum tube along with it.

AS SOON AS he was alone, Tom moved to the door and stared into the blackness beyond the glass, trying to wake up from this strange dream. It couldn’t really have happened. He hadn’t really seen that, had he?

His neural processor replayed the images and informed him of what must have followed Heather getting knocked into the vactube.

She’d had fifteen seconds to be totally conscious, if she’d held her breath. Then her lungs would have ruptured. If she hadn’t held her breath, she might’ve remained conscious for forty-five seconds. It was enough time for her to realize she was doomed, that there was no way back out of the vactube, and her blood would’ve started to boil.

Tom clutched his temples, because he couldn’t focus his brain. He couldn’t really be here, he couldn’t have stood by and seen Heather get murdered. He couldn’t have stood there, and done nothing, as Blackburn turned around and walked away like nothing had happened.

There wouldn’t be any forensic evidence, would there? Her body was in the vactube somewhere, and her neural processor would be utterly obliterated once she was hit by a vactrain going several thousand miles per hour. He felt a hysterical laugh rise inside him, realizing he was the only person, the only person in the world who knew what Blackburn had done.

He stared at the glass, reflecting no image of him, and wondered why he’d stood there and said nothing even after Blackburn decompressed the chamber. Had he been in shock or . . . or had some part of him realized what was about to happen and known it was the only way to neutralize Heather?

He couldn’t figure it out. His brain wasn’t working right.

Then he sprang a foot in the air as Wyatt and Vik’s footsteps scuffed up behind him.

“Okay, the retina scanners are definitely out,” Wyatt said. “Ready to go?”

Everything had transformed for Tom in a few minutes. The lines of the world around him had taken on a stark clarity, and he felt like he could see every jagged detail he’d missed before. They could die doing this. He could get them all killed. Tom felt a great rush of self-doubt. They’d planned this so carefully, but what if they were wrong?

Then his thoughts turned to Yuri, the reason they were doing this. It calmed him.

No. They wouldn’t get killed.

He wouldn’t let it happen. Not this time.

He couldn’t think about Heather right now. He had a task and thinking about this would hobble him, distract him. All he needed to think about was getting into Obsidian Corp., destroying that transmitter, and getting back out. Nothing else mattered until that was done.

“Let’s go,” Tom said.

CHAPTER TWENTY-FIVE

WHEN THE VACTRAIN halted in Antarctica, they darted toward the elevator. Then they waited, invisible in their optical camouflage, for an elevator full of Obsidian Corp. employees to finally come to the Interstice. It took a while. Thirty-eight minutes later, the doors slid open and some of Obsidian Corp.’s personnel strode out. Tom, Vik, and Wyatt rushed straight inside.

Then a message from Wyatt appeared before Tom’s eyes. I’m activating the net-send thought interface now, but I tweaked it so if you want it to actually send, you have to confirm. We don’t need to hear each other’s stray thoughts.

Even now, Tom’s vision glowed with the first thought that always came to him when hooked into a thought interface: Don’t think about boobs. He felt very pleased to select the “Cancel Message” option rather than the “Send” one.

As the elevator rose, Tom felt Wyatt’s hand grab his, and he squeezed hers reassuringly. Vik’s shoulder bumped his during the interminable trip upward, their ears popping.

They flattened themselves against the wall when the next batch of Obsidian Corp. employees stepped into the elevator, then slipped past them into the lobby before the doors closed.

The optical camouflaging concealed them long enough for them to hop straight over the turnstiles without activating the retina scanners, then they pulled up Tom’s mental map. They needed to get to one of Obsidian Corp.’s neural access ports. It was their first task.

They slipped out of the hallways sprinkled with employees and ventured into the sectors of Obsidian Corp. minimally fit for human presence where the lights were dim, the floors lined with power plates for the various machines. This was where Praetorians slid through the halls on a standard patrol, with others in sleep mode, tucked against the walls.

Remember, stay off the floors, Vik thought to them as they waited in the doorway to the machine-heavy sector.

Tom nodded, even though Vik couldn’t see it. Not only would they get electrocuted by the conductive floors powering the Praetorians, they’d set off every alarm in the place if their footfalls tripped the sensors on the ground.

They stood there, so close they were all touching, optically camouflaged inside the doorway, waiting for a Praetorian.

Tom’s heart began to pound. They’d practiced this next part in the Spire twenty-five times, using the old Praetorian in storage. That one couldn’t see through their optical camouflage. Now it would count.

Tom drew a sharp breath when a Praetorian circled around the corner, its curving metallic head atop its pendulous base. It slid toward them down the hallway, and Tom felt like worms were writhing in his gut. One command from a remote operator, and these machines could flood the hallway with poison gas, could electrocute them, could slice their heads off with lasers, or crush them to death. If Wyatt’s code wasn’t perfect, if one of them slipped, if Vik’s fingers weren’t nimble enough, they all died.