Glenn Ford as Prof. Andrew 'Andy' Patterson

Rosemary Forsyth as Vivian Masters Patterson

Dean Jagger as Chad Harmon

Maurice Evans as Harry Masters

Will Geer as Mike Patterson

Eduard Franz as Dr. Konstantin Horvathy

William Conrad as Bart Harris

Robert Pine as Phillip Dunning

William Smithers as Dr. Jerry Fielder

Logan Field as Thaddeus Burns

Dabney Coleman as Agent Shepard

Scott Graham as Weber

James McEachin as Police Detective

Robert Clarke as Dr. Louis Bauier (uncredited)

Lisabeth Hush as Betty Fielder (uncredited)

Mark Roberts as DA Avery Hazelton (uncredited)