Arms dealer Kaltenbach is supposed to turn in a supplier of plutonium explosives to the Federal Criminal Police Office. Kaltenbach hires Tom, an admirer of his daughter Sharon, for the job. Shortly thereafter, an attempt is made on Tom's life, and Sharon is kidnapped by unknown assailants.

Tom's wife Eva travels to Lisbon to investigate the circumstances surrounding his death. To her surprise, her husband, whom she believed to be dead, suddenly appears before her: Tom managed to escape and has gone into hiding to search for the plutonium explosives. Eva is supposed to help him.