A grounded American fighter pilot is switched to espionage on a special job in which he must kill a small-time Paris lawyer suspected of double-crossing France by selling out radio operators to the Nazis.

A German intelligence officer investigates a prostitute's killing in Warsaw during World War II. He lands on three major Nazi generals as suspects, two of whom are also involved in a plot to kill Adolf Hitler.

When Professor Willingdon becomes wary of the nuclear weapons he is helping build, he steals a warhead and threatens to detonate it in London in seven days unless the government begins nuclear disarmament. As Willingdon goes into hiding, Detective Folland of Scotland Yard sets out to find him. Willingdon's daughter Ann also joins the cause, hoping she can talk sense into her father before he causes a catastrophe.