George C. Scott as John Russell

Trish Van Devere as Claire Norman

Melvyn Douglas as Senator Carmichael

John Colicos as Captain DeWitt

Barry Morse as Parapsychologist

Madeleine Sherwood as Mrs. Norman

Helen Burns as Leah Harmon

Eric Christmas as Albert Harmon

Frances Hyland as Mrs. Grey

Ruth Springford as Minnie Huxley

James B. Douglas as Eugene Carmichael

J. Kenneth Campbell as Security Guard

Roberta Maxwell as Eva Lingstrom

Bernard Behrens as Robert Lingstrom

Jean Marsh as Joanna Russell

Chris Gampel as Mr. Tuttle

Voldi Way as Joseph Carmichael

Michelle Martin as Kathy Russell

Janne Mortil as Linda Grey

Terence Kelly as Sergeant Durban

Robert Monroe as Archives Clerk

Hagan Beggs as Coroner

Anna Hagan as Secretary

Antonia Rey as Estancia

Sammy Smith as Doorman

Paul Rothery as Tony Grey

Bruce MacLeod as Security Guard

Fred Latremouille as Airport Guard

David Peevers as Microfilm Clerk

Sera Johnstone as Sara Lingstrom

Adam Earle as Adam Lingstrom

Carl Boychuk as Music Student #1

Bryan King as Music Student #2

Susan Round as Music Student #3

Nicki Steida as Music Student #4

Randolph Blankinship as Pilot #1

Travis Major as Pilot #2

Kyle MacLachlan as Uncredited