Robert Hays

D.H. 'Hank' Mercer / Biff Deegan

Catherine Mary Stewart

Marissa

Christopher Murney

Lt. Greenberg

Fred Gwynne

Victor Greville

Celeste Holm

Claire

Martin Neufeld

Pete

Michael Copeman

Eric Keenleyside

Robin Ward

Louis Di Bianco

Marc Gomes

Lynne Cormack

Lynne Gorman

Jacques Sandulescu

Timothy (uncredited)

Lewis J. Stadlen

Norman Wagstaff (uncredited)