The entire incident took less than five minutes, but now they had a real problem: a soaking-wet SEAL, exposed in an Arctic blizzard. Beaman knew he had no more than a few minutes before Cantrell would fall victim to hypothermia. His lips had already turned a deep blue. His speech was slow and slurred. Beaman had to get him warmed quickly before he went into shock. If that happened, the big SEAL was doomed. Medical treatment was too far away.

Chief Johnston moved upstream a few meters and crossed the ice-covered creek. When he reached the far shore, he signaled for the rest of the team to join him while he hollowed out a snow cave in the shelter of a large boulder. In minutes, the team moved the now delirious Cantrell into the shelter of the cave, stripped him of his stiffening clothes, and slipped him into a sleeping bag. Martinelli and Hall climbed in on either side of him, warming their teammate with their own body heat.

Cantrell began to shiver uncontrollably, but slowly, the combined warmth of the team brought him back from the edge. It took hours, precious hours they needed to get to Polyarnyy on schedule, to save him, but no one complained.

While everyone else was working with Cantrell, Johnston slipped back down to the stream. Something wasn’t right here. They were in the Arctic. Temperatures were well below zero and had been for months. The ice here should be several feet thick and hold up even a big lug like Cantrell.

When Johnston saw steam rising from the open water, he thought he had the answer. As he got closer, he could smell the rotten-egg odor of sulfur. The salty taste of the water confirmed his suspicion. A mineral hot spring welled up beneath the stream right here in this spot. The combination of the high mineral content and the warm uprising water prevented a thick layer of ice from forming.

They would have to be more careful. Hot springs were common up here. Stumbling across another one like this could prove fatal.

Johnston cursed himself. He should have been watching for this. One of his men was in trouble and the mission delayed because he and the team had let their guard down.

The chief kicked hard at the snow as he headed back to the cave.

Jon Ward waited on the pier at Faslane as the Toledo steamed up the loch. He spotted Joe Glass standing on the bridge. His old XO sure seemed to have graduated into one fine skipper. And where Ward was sending him would tax every bit of Glass’s skill and bravery.

It was just after nightfall at the British submarine base. Beyond the bright lights on the pier, the world was dark as two big Royal Navy tugs pushed Toledo snugly against the rubber camels alongside the pier.

“Welcome back, Joe. Sounds like you’ve been busy,” Ward yelled up at Glass.