The sole survivor of an interplanetary rescue mission searches for the only survivor of the previous expedition. He discovers a planet ruled by apes and an underground city run by telepathic humans.

Cornelius: They will dissect you! And they will kill you! In that order!
Ursus: The only good human... is a dead human!
Cornelius: If you are caught by the gorillas, you must remember one thing.
John Brent: What's that?
Cornelius: Never to speak!
John Brent: What the hell would I have to say to a gorilla?
Nova: Taylor!
Dr. Zaius: Someone, or something, has outwitted the intelligence of the gorillas.
Dr. Zira: That shouldn't be difficult.
John Brent: When may we hope to be released?
Caspay: You may hope whenever you wish.
[last lines]
Ending Voiceover: In one of the countless billions of galaxies in the universe, lies a medium-sized star, and one of its satellites, a green and insignificant planet, is now dead.
Mendez: May the Blessings of the Bomb Almighty, and the Fellowship of the Holy Fallout, descend upon us all. This day and forever more.
Congregation: [singing] Amen!
Negro: Mr. Taylor, Mr. Brent, we are a peaceful people. We don't kill our enemies. We get our enemies to kill each other.
Caspay, Negro: I reveal my Inmost Self unto my God.
Albina, Fat man: Unto my God.
Congregation: [singing] Unto my God!
Mendez: Glory be to the Bomb, and to the Holy Fallout. As it was in the beginning, is now, and ever shall be. World without end. Amen.
Mendez: [praying] The heavens declare the glory of the Bomb, and the firmament showeth His handiwork.
John Brent: [indicating Nova] She can't help you. She can't even talk! Don't harm her.
Albina: *We* never harm anyone, Mr. Brent. *You're* going to harm her.
Ursus: The only thing that counts in the end is power! Naked merciless force!
Dr. Zaius: You ask me to help you? Man is evil! Capable of nothing but destruction!
John Brent: That thing out there, an atomic bomb... is your god?
Taylor: [as Nova slowly dies, gunned down by a gorilla] Well, that tears it. Maybe we should just let the world blow up. The gorillas, every damned... what it comes to.
[with a dry little man-sob of despair]
John Brent: [Intense, full of fury] Taylor, come on. Come on!
Taylor: Yeah.
John Brent: [Dr. Zira pours a powder on Brent's wound] Ow! What is that damn stuff?
Dr. Zira: You wouldn't know if I told you. Just relax. Among other things, I'm a trained vet.
Ursus: What is more dangerous than famine, Doctor?
Dr. Zaius: The unknown.
John Brent: [to a sleeping Nova] Are you... what we were... before we learned to talk and made a mess of everything?
Ursus: He bleeds! The Lawgiver bleeds!
Dr. Zira: Gorillas are cruel because they're stupid! All bone and no brain!