Stenseth restarted the motor and cruised to the southeast for ten minutes, then cut the motor again. Repeated shouts through the fog went unanswered. Stenseth motored on, repeating the process once more. When the last round of shouts fell empty, he addressed the crew.

“We can’t afford to run out of fuel. Our best bet is to run east to King William Island and try and locate some help. Once the weather clears, the submersible can be found easily. And I can tell you that Pitt and Giordino are probably a lot more comfortable in that sub than we are.”

The crew nodded in agreement. Respect ran high for Pitt and Giordino, but their own situation was far from harmless. Getting under way once more, they ran due east until the outboard motor sputtered to a halt, having sucked dry the first can of gas. Stenseth switched fuel lines to the second can and was about to restart the motor when the helmsman suddenly cried out.

“Wait!”

Stenseth turned to the man seated nearby. “I think I heard something,” he said to the captain, this time in a whisper.

The entire boat fell deathly quiet, each man afraid to breathe, as all ears were trained to the night air. Several seconds passed before they heard it as one. A faint tinging sound in the distance, almost like the chime of a bell.

“ That’s Pitt and Giordino,” Dahlgren shouted. “Has to be. They’re tapping out an SOS on the Bloodhound ’s hull.”

Stenseth looked at him with skepticism. Dahlgren had to be wrong. They had moved too far from the submersible’s last-known position. But what else could be signaling through the bleak Arctic night?

Stenseth engaged the outboard motor and sailed the tender in an ever-widening series of circles, cutting the throttle at periodic intervals to try to detect which direction the sound was coming from. He finally noted a rising pitch emanating from the east and turned in that direction. The captain motored slowly but anxiously, fearful that the tapping might cease before he had determined a true bearing. The fog blew in thick wisps while the morning dawn still struggled to appear. As close as they might be, he knew it would be all too easy to lose the submersible if it fell silent.

Fortunately, the clanging went on. The rapping only grew louder, audible even over the rumble of the outboard. Changing course with slight shifts to the tiller, Stenseth zeroed in on the sound until it echoed in his ears. Cruising blindly through a dark bank of fog, he suddenly cut the throttle as a huge black shape rose up in front of them.