The world is shocked by the appearance of three talking chimpanzees, who arrived mysteriously in a spacecraft. Intrigued by their intelligence, humans use them for research - until the apes attempt to escape.
Roddy McDowall
Cornelius
Kim Hunter
Dr. Zira
Bradford Dillman
Dr. Lewis Dixon
Natalie Trundy
Dr. Stephanie 'Stevie' Branton
Eric Braeden
Dr. Otto Hasslein
William Windom
The President
Sal Mineo
Dr. Milo
Albert Salmi
E-1
