Peter Graves

Character: Jeff Knight

Eileen Dietz

Character: Dana

Paulette Breen

Character: Lena

Frank Ashmore

Character: George Walker

Dick Sargent

Character: Dr. Jameson

Zale Kessler

Character: Dr. Nelson

William Bufkin

Character: Clone

Tony Haig

Character: Jack

Boyd Holister

Character: Senator

Keenan Wynn

Character: Jake Noble

Lurene Tuttle

Character: Anna Noble

James Mantell

Character: Ricky Knight

David Hooks

Character: Richard Knight

Frank Birney

Character: Reporter Birney

Rick DiAngelo

Character: Guide #1

Eugene Robert Glazer

Character: Guide #2 (as Gene Glazer)

Tim Donnelly

Character: Richard (as Timothy Donnelly)

Chuck Hayward

Character: Walker Man