Equinox

?

Edward Connell

David Fielding

?

Barbara Hewitt

Susan Turner

?

Jack Woods

Asmodeus

Frank Bonner

Jim Hudson

?

Robin Christopher

Vicki

?

James Phillips

Reporter Sloan

?

Fritz Leiber Jr.

Dr. Arthur Watermann

?

Patrick Burke

Doctor Branson

?

Sharon Gray

Nurse

?

Louis Clayton

Old man in cave

?

Norvelle Brooks

?

Irving L. Lichtenstein

?

James Dwion

The Orderly

Forrest J. Ackerman

Doctor on Tape Recorder (voice) (uncredited)

?

Jack H. Harris

Detective Harrison (uncredited)