Mac stared at the steel vessel growing larger in his binoculars. “Angus, I believe it was Robert Burns who once said, ‘No man can tether time or tide. Time is short and the tide is out.’”

Angus grinned. “Those tha’ cannae be counseled cannae be helped.”

“Who said that?”

“My father, before he’d beat my arse with a hickory switch. Jist a wee love tap, he’d say.”

“What say we give MJ-12 a wee love tap?”

We were powerless, our sub lying on the floor of Prydz Bay, weighed down by our two lasers. Silt had buried all but the Valkyries and the top of our cockpit dome. The Tortuga’s keel was just visible in the distance, anchored in 320 feet of water.

We felt the rumble of the steel beast before we saw it, its 300,000 tons displacing the surface while vacuuming up the bottom, its presence causing the ice sheet to reverberate.

Then I saw the 1,100-foot supertanker’s bow converge upon the Tortuga’s starboard flank, and for the second time that morning I prepared to meet my Maker.

The process of slowing a supertanker must be initiated miles in advance using a braking pattern called a slalom, which veers the ship back and forth from starboard to port while her engines run full astern. Mac had either seriously miscalculated Newton’s Law of Conservation of Momentum, or he simply didn’t give a damn.

The prow of the supertanker struck the exposed flank of the Tortuga like a steadily moving train plowing through a double-decker aluminum bus, crushing the starboard infrastructure while its submerged bulb-shaped bow scooped up the vessel’s disfigured hull and carried it away with hardly a drop in speed or forward momentum.

Passageways crumpled. Water blasted through shredded steel plates. Internal pipes and cables ruptured. From Angus and Mac’s perspective, it must have appeared as though the supertanker had bitten off a chunk of the Tortuga’s ribs. From our perspective, it looked like a megalodon had snatched an orca in its jaws and was carrying it off to be consumed.

And then an unseen force swept us off the bottom into the eye of a hurricane.

I squeezed my eyes shut and held on as the vortex created by the two passing ships inhaled us, spinning us end over end toward the supertanker’s propeller shafts, the blades churning in reverse.

Jonas was a rock. Knowing the Tonga’s impact would shut down power to the Tortuga’s sonar array, he focused only on his command console. The moment the lights powered on he jammed the controls hard to port and pulled us away from the spinning blades into a steep dive.

Moments later a submerged wall of ice materialized into view. Jonas quickly honed in on the Loose Tooth Rift’s jagged chasm, which harbored the cavernous opening created nearly six hours earlier by the Tethys.