Barbara Bain (Dr. Helena Russel)
Stuart Damon (Guido Verdischi)
Clifton Jones (David Kano)
Martin Landau (Commander John Koenig)
Zienia Merton (Sandra Benes)
Catherine Schell (Maya)
Nick Tate (Alan Carter)
Tony Anholt (Tony Verdeschi)
Prentis Hancock (Paul Morrow)