Keir Dullea

Devon

Robin Ward

Garth

Gay Rowan

Rachel

William Osler

Computer / Host

James Barron

Garth's Father

John Colicos

The Governor

Gillie Fenwick

Old Abraham

Scott Fisher

Small Boy

Paul Geary

The Guard

Kay Hawtrey

Garth's Mother

Sterling Hayden

Jeremiah

Dominic Hogan

The Priest

Michael Kirby

The Captain

Barry Morse

Shalith

George Naklowyck

The Deputy

Harvey Hart