The borehole was now a clogged artery of white ice. Powering up the Valkyries, Jonas pressed the Manta’s nose to the frozen gauntlet, which quickly liquefied and inhaled us into its dark, widening orifice.

We were on our way.

36

“How puzzling all these changes are!
I’m never sure what I’m going to be, from one minute to another.”

—Lewis Carroll

The sub’s lights illuminated a near-vertical shaft of ice so crystal-clear that Jonas struggled to discern the boundaries of the funnel. After the Manta’s fifth collision with the borehole’s walls, he shut down the exterior lights and relied strictly on the cockpit’s night-vision glass, which generated a view that reminded me of a miniature medical camera plunging down an olive-green esophagus.

After descending nearly six hundred feet, the passage leveled out, depositing us in a shallow sea of meltwater that separated the bottom of the ice sheet above our heads from the floor of Prydz Bay. Squeezed between these two titanic forces, the water pressure within this narrow, seemingly endless cavity registered an eye-popping 12,656 psi, the weight above us muffling everything but the sound of our breathing.

Visibility was limited to an olive-green patch that extended ten to twelve feet in every direction. For several minutes we maintained a snail’s pace through this vast, dark, liquid space, until the overwhelming sensation of claustrophobia sent Jonas fumbling for the lights. He flipped the switch, and our beams illuminated a hidden chamber of breathtaking beauty.

For millions of years the ice sheet had surfed this watery conveyor belt as it inched its way across East Antarctica before slaloming along the Amery Basin into Prydz Bay. Perpetually melting and refreezing, the bottom of the glacier appeared a rich azure-blue, its sculpted patterns and textures creating a three-dimensional mosaic so mesmerizing I was tempted to ask Jonas to direct a light at the ceiling, just so I could absorb its incredible details.

Complementing this chapel of art was a boundary of fresh water so pure and clear it actually magnified our twin beacons of light, extending visibility for miles. As for what resided below, for now it was dark silt. But that would change.

Jonas was still too overwhelmed by grief to allow himself to be dazzled. “Zach, this subterranean waterway seems to run forever. How do we know which direction to go?”

“We need to follow the Amery Ice Shelf inland about 340 miles, where it will meet the Lambert Glacial Basin. A subglacial river with a northern outflow should merge with this meltwater. We follow it southeast into Lake Vostok.”