A veteran Russian spy is brought out of retirement to be sent to the West to do an important sabotage job. However, he finds himself falling in love with an attractive British double agent.

Lorne Greene
as Peter Vanin

Rachel Roberts
as Megan Thomas

Anthony Quayle
as Col. Malendin

James Donald
as Sir Martin Rolfe

Harry Andrews
as Gen. Kirk

Patrick Magee
as John Flack

Patrick Newell
as Julius Bates

Raymond Huntley
as Supt. Pode

Olaf Pooley
as Igor Trubenoff

Janina Faye
as Elena Vanin