“Guys, I’m wiped. Maybe we ought to sleep in shifts.”

“Go on, Doc. I just popped a caffeine pill.”

“Get some rest, Zachary. I will monitor the sonar array.”

The Barracuda leaped ahead, jumping from three knots to twenty within seconds. Brown flakes flew past the acrylic glass like a dirty blizzard.

Settling back in my seat, I closed my eyes…

13

“This anomaly is so large that it cannot be the product of a daily change in the magnetic field.”

—Michael Studinger,
NASA project scientist mapping Lake Vostok’s magnetic anomaly

PING.

PING… PING… PING.

The acoustic disturbance jump-started my heart like a bad alarm clock. Locating my headset, I spoke into the mouthpiece, the soothing calm of my catnap eradicated. “What’s wrong? Ben, why are you pinging?”

“We’ve reached the southern face of the ridge. You were right; the plateau runs straight up to the surface. Ming suggested we go active on sonar to see if we could find a breach in this underwater gauntlet.”

I stole a quick glance at my control console. The depth gauge read 817 feet. Using my night glasses, I glanced out to starboard. We were heading west, moving parallel to an imposing cliff face covered in algae.

“How much of the plateau have you surveyed on sonar?”

“Only about four miles, but we’re pinging every three hundred feet. All this algae deadens the sound.”

Ming set off another ping. I switched my headphones to SONAR, following the rippling sound wave on my monitor as it reflected off the plateau, my eyes catching a blip dancing in and out along the right edge of my screen.

“There’s something registering on our acoustic periphery.”

“Tell me it’s an underground river.”

“Sorry. It’s a biologic. Not a small one, either.”

“How big?” Ming asked.

“I don’t know. Maybe ten meters. It’s about a kilometer to the west, hovering along the face of the plateau close to the surface. But stay calm. For all we know, it could be a giant sea cow. They were pretty common during the Miocene.”

“A sea cow? How do you know that? Did you hear it mooing?”

“Take it easy, Ben. The way it’s moving along the rock face suggests it’s a plant-eater.”

Ben stared hard at his sonar screen. “Ming, ping again.”

The gong raced out in all directions, the reflection appearing on our monitors. A bright line swept clockwise across the grid, illuminating the blip to the west—along with a second object rising slowly away from the bottom a thousand yards south of our position.

Oh, hell.

“Zachary?”

“Yes, Ming, I saw it. Ben, bring us as close to the plateau as you can, then ascend the sub so that we’re on an intercept course with that first blip. Ming, no more pings.”

“That second blip—it’s a predator, isn’t it?”

“I think so.”

“How big?”

“Trust me, Ben, you don’t want to know.”