Vic Perrin

Control Voice (voice) (uncredited)

Ivan Dixon

Sgt. James Conover,Major Harold Giles

John Hoyt

Bifrost Alien,Professor Hebbel,Emmett Balfour

Robert Culp

Trent,Allen Leighton,Paul Cameron

Robert Duvall

Adam Ballard,Louis Mace

Willard Sage

First Reporter,Coulter,Chief of Staff

Jason Wingreen

Fred Severn,Bill Turner,Coroner Leland

Edward Platt

Mr. Terrence,Dean Radcliffe,David Hunt (as Edward C. Platt)

Douglas Henderson

Dr. Tillyard,Detective Lt. Runyan,Dr. Paul Fredericks (uncredited)

Ben Wright

Elder of Luminos,Gen. Benton,Philip Exeter Dundee