Paige started to respond, then stopped and frowned, as if something that’d been bothering her for the past couple minutes had finally surfaced. “It’s one thing to send us a message through the Breach, but why are they sending dangerous things like entities? If they created a wormhole to tell us something—”
“They didn’t,” Garner said. “They didn’t create the wormhole. Or the entities passing through it. That stuff is all archaic, even on the timescale of the universe. Whoever created it disappeared long ago. Probably a billion years back. These old transit tunnels full of relics are all that’s left of them. The Deep Sky’s original purpose was simply to study the tunnels—a whole network of them, discovered earlier by the first robotic probes that went out to neighboring stars. The Deep Sky was built from top to bottom as a dedicated research ship, with the means to investigate and even exert some control over wormholes. In the end, the crew used that capability to cause the Breach to open here on Earth, in our time. They rerouted a single tunnel to some degree—enough to make sure that the VLIC’s first shot in 1978 would connect with it, and not to a primordial one teeming with parasite signals. It took an ungodly amount of power to move the tunnel, and as soon as they’d done it, they had to begin generating and storing more power to move it again—this time so they could tap into it on their end. That process—repowering—would require a little over thirty-eight years, and be completed on June 5, 2016, by our calendar. During all the time in between, they had no way of stopping the flow of entities through the system. The most they could do was set up a kind of reverb effect in the tunnel, a very specific disturbance in which they could encode a message.”
“The Breach Voices,” Paige said.
Garner nodded. “Along with the initial impulse that would make a translator of whoever was standing closest when the Breach opened. That was some kind of neurotechnology that’s probably a few centuries ahead of ours—and obviously not perfected, given the damage it did to Ward.”
Travis let all the information settle in his mind, to the extent that it could.
“The tunnels are abandoned?” he said.
Garner nodded again. “Ancient ruins. Though many of the systems engineered into them are still running. Including defensive measures. Safeties.”
“Like what?” Paige said.
“The message covered it all pretty briefly. I got the sense that it would take a textbook to really explain it, but the basics were straightforward enough. One of the safeties is the resistance force inside the Breach, which doesn’t allow you to enter from our end. All the tunnels have that, to protect against the threat of outsiders—like us—tapping in at some random spot and immediately traveling throughout the network. Which makes sense, when you think about it. If you strung the universe with these tunnels, you’d never know when some hostile race might evolve somewhere, punch in and show up in your backyard.”
“So how do you go through it?” Bethany said.
“You need a tumbler,” Garner said.
Everyone waited for him to go on.
“That’s the best stab at translating the word from their language—whoever built the tunnels. Tumbler, as in the mechanism inside a lock. The way it works is, any two points connected by a tunnel need to be authorized before someone can travel between them. Think of it as unlocking them. And the only way to do that is for a single individual—a single conscious mind—to think the same complex thought outside both entry points first. You see how that works? It means at least one person has to make the trip the old-fashioned way—in a ship—before the tunnel lets anyone through. So you’d open one entrance, think a specific thought near it—an exchange from Twelfth Night, say—and then chug across space at ship speed to the other entrance, and think the exchange again. Same mind, same thought—that’s what the tunnel listens for. Until it hears that, it won’t open.”
Travis thought he understood the concept, and the reasoning behind it. “It means no new civilization can come out of the blue and expand their presence in space too quickly, right? They can’t push their boundaries any faster than ships can travel.”
Garner nodded. “And a person stuck with that job, unlocking a tunnel’s two ends, is the tumbler. In this case it’s you. I’m sure you can guess why.”
Travis considered it. He stared at the seatback in front of him, then turned to Garner. “Because I’ve already made the trip. There’s one of me on that end already, and one of me on this end.”
Another nod.
“Will that actually work?” Travis said.
“Same mind, same thought,” Garner said.
“So what is the thought? Did they put it in the message?”
Garner shook his head. “They’ll give it to you in person. After you go through to their end.”