He watched Travis for the confusion he obviously expected. Travis saw Paige’s and Bethany’s eyes narrow too.
“How will you go through the tunnel if you haven’t unlocked it yet?” Garner said. “That’s another safety—one for the tumbler’s own protection. The term for it translates to something like ‘scouting.’ You get to do it just once, back and forth—a single round-trip. The logic of it goes like this: a tumbler usually has to unlock a tunnel’s first end, then travel for a very long time across space to unlock the second end. But before he unlocks the second end, he can choose to enter the tunnel there, just once, and go through it to take a good look at the first end again. To scout it.”
Travis saw the point—was pretty certain he did, anyway. “After all that time had gone by, while you were crossing space in a ship, it’d be risky to reach the far end of the tunnel and just open it blindly. What if things back home had changed by then? What if there was something dangerous waiting to come through?”
Garner managed a smile. “Hell, you might open the tunnel and get a magma flow. Or seawater pressurized at a mile’s depth. A lot can change, given enough time, and it could take thousands of years for a ship to travel the distance required. It could take longer. The Deep Sky’s crew isn’t worried about that in this case, obviously. As far as I can tell, they just want to speak to you before you fully open the tunnel. About what, I have no idea.”
“So the other me,” Travis said, “the one aboard the Deep Sky, will unlock the far end of the tunnel first, and once that’s done, I can make a single trip to their side and back. A scouting trip.”
“That’s the plan, as I understand it.”
Travis stared at him, thinking it all through. Random questions remained. Trailing ends. One in particular.
“Tell us about the filter,” Travis said.
Garner looked surprised. “How can you know about that?”
“Beyond that word, we don’t know about it,” Travis said. “I’ll explain the how later.”
He held Garner’s gaze and waited for him to speak.
“I don’t know much more than you do, I’m afraid,” Garner said. “The filter was always the strangest part, to me. And the scariest, I suppose.”
“Why?” Paige said.
Travis noticed Bethany looking around at everyone like she’d missed something. Which she had; they’d never told her anything about this. Travis caught her glance and said, “I’ll tell you later.”
She nodded, but the confusion stayed in her expression.
“The filter was the one thing Ruben Ward chose to leave out of the written message,” Garner said. “He never dictated it to Nora during his stay at Johns Hopkins, and only spoke briefly of it to the nine of us, later that summer. He was afraid to share the details, he said. He worried that if we knew about that part, we’d back out. He said it was something absolutely necessary, but also terrible, and that it was best if no one but you, Travis, ever learned about it.”
“Do you think it’s something that happens to me when I go through the Breach?” Travis said. “Something that changes me? Am I what gets filtered?”
Again Garner looked surprised, but only mildly so this time. “That’s more or less what I’ve imagined all these years. But it’s no more than a guess—mine is as bad as yours.”
Travis nodded. As he had in the mine shaft, he let the subject slip from his thoughts. There were only so many ways he could hold it up to the light. He looked at Garner again.
“The nine of you were supposed to get me into Tangent,” Travis said. “Get me in and then, as you said, tell me everything at the last possible moment.”
Garner nodded.
“So what did you think,” Travis said, “when I ended up in Tangent without your help, in the summer of 2009?”
“That very strange things happen in connection with the Breach. And that it couldn’t be a coincidence.”
“It wasn’t. I’ll explain that later too.”
“I’d appreciate it.”
Travis considered something else. “You were prepared to hit Border Town with a nuke, back then, when Aaron Pilgrim took control of the place.”
“The Breach would’ve survived. You can’t imagine the forces that stabilize it. All that stopped me was that you wouldn’t leave the place. I had no choice but to go along with the approach you suggested.”
For a while after that, nobody spoke. The heavy engines droned and the lit-up nightscape slid by, far below.