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
Professor John Malcolm Francis Willingdon
André Morell
Superintendent G.W. Folland
Olive Sloane
Goldie Phillips
Sheila Manahan
Ann Willingdon
Hugh Cross
Stephen Lane
Joan Hickson
Mrs. Emily Georgina Peckett
Ronald Adam
Arthur Lytton, the Prime Minister
Marie Ney
Mrs. Willingdon
