When Boss saw his own hand dropping away from his body, severed at the wrist, he knew he had to act fast or he was a dead man. He was already groping for the tourniquet on his belt as he rolled from the icy steel decking. He plunged into the dark, icy water with a heart-seizing abruptness. In his multifaceted career, Boss had taken the Army’s Combat Water Survival Training. He’d also taken cold weather training with the Norwegian Army, which had required jumping through a hole cut in a frozen lake.

