Fergus Frew thought he knew what to expect when he signed up with the Navy's demolitions team. But as the Korean War rages on, Fergus and his fellow divers -- AKA "frogmen" -- are tasked with more than just scouting mudflats. Soon they're planting mines. And sabotaging tunnels, bridges... and even fishing nets. Strangest of all, it falls to Fergus to transport a spy into the country -- and that means traveling far from Navy-controlled waters.