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.
Barry Jones
André Morell
Olive Sloane
Sheila Manahan
Hugh Cross
Joan Hickson
Ronald Adam
Marie Ney
Joss Ackland
Marianne Stone
John Stratton