Following the Pearl Harbor attack, the U.S. government enlists a group of Secret Service agents under the tutelage of seasoned World War I veteran Robert Emmett Sharkey. Unbeknownst to them, among the recruits known as 'O-77,' there lurks a German double agent on a mission to uncover the date and location of the Allied Front in Europe. Sharkey eventually identifies the spy but cleverly feeds them fabricated information to mislead the Germans.
However, suspicion grows within the enemy ranks, leading to the murder of one of the agents tasked with a perilous mission: kidnapping a significant collaborationist in France. With no time to train another rookie, Bob makes the bold decision to head to Le Havre himself, determined to complete the mission and eliminate the German agent, if possible.
