Submarine Alert plot
"Calling All Agents! STAND BY FOR THRILLS! ADVENTURE! ACTION!"
On the mainland in America, spies work for the Nazis, passing information about departing oil tankers to a Japanese submarine operating just off the coast. A stolen prototype shortwave transmitter is used to send this data. Lew Deerhold, one of the best radio experts of the time, is fired by order from the FBI. Deerhold, who has to take care of his sick daughter alone, is now out of work. It is hoped that he will be approached by the Nazis to work for them, after which he can be tracked and the spy network broken up. When Deerhold, ignorant of their background, accepts the spies' offer, he is soon swept into a maelstrom of betrayal and danger.