The Tethys had most likely forged its own tunnel through the glacier, its superheated bow plates eliminating any risk. I thought about searching for their borehole, but we were already six hours behind.

Gritting my teeth, I guided the sub through the horizontal channel.

It took full throttle just to enter the restricted passage. The ungodly current rocked the sub, slamming the cockpit repeatedly against the ceiling of ice and grinding its undercarriage into the gravel riverbed.

Jonas woke up. Taking command of the pitching submersible, he powered up the Valkyries and ignited the lasers, creating a vacuum effect that accelerated the Manta smoothly through the widening crawl space.

“Guess I should have used the lasers to begin with, huh?”

He shot me a pissed-off look. “Next time wake me.”

“I was afraid you might not risk it.”

“Obviously you have me confused with someone who has something to live for.”

“Be careful what you say. I had another dream.”

“Which planet were you visiting this time? Uranus?”

“The dream took place on Earth, about twenty years from now. Brandy and I were still married, with three kids and a slew of grandkids. Not sure what year it was, but it was Christmas, give or take a day—the day the Yellowstone Caldera erupted.”

Jonas looked at me, incredulous. “Was this real or just one of those multiverse things?”

“There’s no way to tell; it hasn’t happened yet. Obviously. But I don’t think it’s a coincidence that it parallels the event that must have destroyed Charon.”

“Zach, scientists have known about the Yellowstone Caldera for decades. You think a dream is going to convince the authorities to take the threat any more seriously?”

“No, but I do think the dream serves a purpose. I just haven’t figured out what that is yet. What’s our ETA to Vostok?”

“How the hell should I know? We’re still over two hundred miles away. Who knows if we’ll even get out from under this giant ice cube?”

As if the glacier heard him, the passage suddenly reopened, depositing us back in the main river.

For the next thirteen hours, we forged our way to the southwest, averaging eighteen knots. We stretched and ate and relieved our bowels and bladder, and we watched movies over the computer and alternated piloting duties with restless catnaps. Finally, the waterway twisted to the north, the riverbed dropping away several hundred feet as the ice sheet receded overhead, creating a six-foot space of air into which we surfaced.

Lake Vostok. The northern basin.

We had arrived.

38

“The rule is jam tomorrow and jam yesterday—but never jam today.”

—Lewis Carroll

Migrating from the ocean, a salmon will fight its way upstream to return to the river where it was born so it can spawn and die, completing its circle of life.