“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.