John Gregson

Inspector Parnell

Alec Clunes

Anthony Chester

Robert Shaw

Marlowe

Helen Cherry

Robbie

Betty McDowall

Maggie Parnell

William Hartnell

Freddie Maddox

Harry Fowler

Smiley

Alan Wheatley

Assistant Commissioner Bewley

Kenneth Cope

Sergeant Grey

Ernest Clark

Police Doctor

Noel Howlett

Brain Specialist

Renée Houston

Masie Maddox

Piers Bishop

Jonathan Chester

Frank Hawkins

Mr. Tamplin

Ray Smith

Mr. Briggs

Lance Comfort