Terence Longdon
— Mark Robert Kingston
Donald Gray
— Inspector Wills
Diane Clare
— Mary Johnson
Robertson Hare
— Ronald Fortescue
Dermot Walsh
— Prof. Henry Taylor
Jill Hyem
— Joy Clark
Felicity Young
— Jill
Douglas Muir
— Detective Sergeant Willoughby
Edwin Styles
— Sir Lionel
Tony Thawnton
— College Tutor