When a little girl is knocked down it is discovered that there are only three donors of the right blood type to help with a life-saving operation. One is a murderer awaiting execution, one an atomic scientist selling secrets, and one an international footballer about to get his hundreth cap.

Reparto

Dermot Walsh

John Bell

Colin Tapley

Dr. Lloyd

Anthony Dawes

Sergeant Phillips

Patrick Jordan

Jimmy Regan

Edward Ogden

Tommy Day

Sidney Vivian

Shaw

Garard Green

Professor Graham

Glyn Houston

Inspector Harris

Zena Walker

Joan Bell

Helen Forrest

Mrs Day