While dining alone and ordering steak in a Lisbon restaurant, where he’s to make contact with a member of the local underground conspirators, a frantic pretty lady named Irene (Hedy Lamarr) joins him as she’s fleeing from the police after the man she passed on a note to was slain but managed to burn the message. It turns out she’s married to an official from the German embassy Hugo Von Mohr (Victor Francen), which leaves Vincent not trusting her. When Vincent spends a romantic afternoon alone with Irene and returns to his hotel to brief the secret agent in his knowledge of Nazi procedures as arranged by the local underground leader Ricardo Quintanilla (Sydney Greenstreet), he finds the agent just before he dies urging him to contact Quintanilla to tell him that the killer took the valuable coin. The police were tipped off and Vincent gets arrested for the murder by Capt. Pereira’s men of the Portuguese police. In a daring escape, Vincent returns to the fishing village outside of Lisbon where one of the spies, Bernazsky (Peter Lorre), arranged for him to find safety with freedom supporter Miguel. Through Miguel’s daughter Rosa, Vincent again makes contact with the local underground. Quintanilla believes there’s a traitor among his spy network and sets a trap for that person in the casino.