Taylor's spaceship crashes off California's southern coast in 1973. Inside are three talking apes - Zira and Cornelius, along with another scientist, Dr. Milo, having managed to escape the destruction of Earth in the last movie and travel back in time. Milo is killed in Los Angeles' zoo by a non-civilized gorilla, and this prompts a pregnant Zira to baptize her son "Milo".
Considering the dangers of talking apes, the US Military starts chasing them, prompting Zira, Cornelius, and Milo to get hidden in Armando (Ricardo Montalbán)'s circus.
The sequel to this movie, Conquest of the Planet of the Apes, was released in 1972.
This movie contains examples of:
- Adults Are More Anthropomorphic: Zira, Cornelius and Dr. Milo are played by human actors in ape make-up, and as such, they are bipedal and have largely human-like body proportions. Zira's baby is played by a live baby chimpanzee.
- Bait-and-Switch: The movie opens up with a shot of a beach, which looks similar to the one in the first movie, which the audience would assume is the exact same one. Then we see a modern helicopter approaching.
- Berserk Button: Apes, when called "monkeys".
- Big Bad: Dr. Otto Hasslein fills this role, being the man actively seeking to kill Cornelius, Zira and their child in order to try and prevent the coming of the Planet of the Apes.
- Cosmopolitan Council: The President's Committee of Inquiry "consisting of leading experts in all fields relevant to a situation whose implications - whether zoological, biological, psychological, medical, mathematical, historical, physical or even spiritual - are numberless."
- Cruel Mercy: The President's Committee of Inquiry decided (on a majority vote) that Cornelius and Zira are allowed to live, but their unborn child has to be aborted and they must be sterilized to prevent another pregnancy.
- Cultural Posturing: Despite Cornelius' defensive Humans Are the Real Monsters commentary, anyone who's seen the previous film knows he's glossing over the many, many faults of apedom, including the fact that they were just as violent towards their own as humans—as seen when Zaius and Urko had armed gorilla soldiers break up a peaceful protest by beating the protestors senseless.
- Dead Guy Junior: Zira names her son after Milo, her late colleague.
- Does Not Like Spam: Zira, contrary to the popular stereotype of primates and bananas, dislikes bananas. In fact, she finally gives the game away about her sapience and vocal abilities when, overhearing some human scientists wondering why she didn't eat the fruit she'd reached, she can't resist informing them of this fact.Zira: Because I loathe bananas!
- Double Don't Know: Dr. Hasslein has discovered from Zira that one day apes will become sentient, and the world will be destroyed in the year 3955, so he tells the President of the United States that, to prevent a Stable Time Loop, he should have the two Chimpanees from the future, Cornelius and Zira, killed.President: Convince me.Dr. Hasslein: By their own testimony, we know that one day apes will acquire the power of intelligent speech. By Zira's testimony, we know she's pregnant with child. By my own testimony, we know it's possible for this child - provided, of course, that we permit its birth - to bear or beget a talking ape with a dumb one... in a present-day jungle or a present-day zoo.President: But do you believe, by deliberate present-day action, we can neutralize that possibility, that we can alter the future?Dr. Hasslein: Yes, Mr. President, I do.President: Do you also believe that we should? Given the power to alter the future, have we the right to use it?Dr. Hasslein: I don't know. I've wrestled with this, Mr. President, I just don't know.
- Zira, due to her pregnancy.
- Dr. Branton, upon hearing Zira talk for the first time.
- Fantastic Racism: Zira isn't fond of gorillas in general.
- Freudian Slip: "As to humans, I've dissect — I've examined!"
- Guilt by Association: One of the interrogators believes it doesn't matter if the chimps aren't as warmongering as the gorillas since they're "all monkeys".
- Henpecked Husband: Discussed and Played for Laughs:Interrogator: [referring to Cornelius] Does the other one talk?
Cornelius: Only when she lets me.
(Everyone in the courtroom, including Zira, has a good laugh)
- Humans Are the Real Monsters: While being interrogated, Cornelius tells them the destruction of the Earth was the fault of a man-made weapon.Cornelius: Man destroys man! Apes do not destroy apes!
- In Vino Veritas: Dr. Hasslein obtains all of the information regarding the Planet of the Apes and how it came to be by making Zira drunk and talking to her while using a hidden tape recorder.
- Jerkass: Dr. Hasslein is this from the very first second he's on-screen. Overly paranoid about the apes and looking to find out about their society (by making Zira drunk) and when the truth of the apes' history is known, the first thing he can think of is to Leave No Survivors (with killing a defenseless baby and neutering at his most benevolent — at the climactic confrontation, he even wastes all of his ammo shooting the poor baby rather than deal with his parents, one of which has a gun of his own).
- Jump Scare: An in-story example. While the main characters are walking around a museum, Zira faints after she happens upon a surprisingly fearsome-looking statue of a yeti.
- Killer Gorilla: Gorillas, in general, are considered violent and militaristic, and a non-evolved gorilla kills Dr. Milo.
- Little "No": "On an historic day, which is commemorated by my species and fully documented in the Sacred Scrolls, there came Aldo. He did not grunt. He articulated. He spoke a word which had been spoken to him time without number by humans. He said, 'No'."
- Match Cut: The head councillor is about to lay down the grovel (as they voted to have the baby killed and the parents sterilized), then we cut to Cornelius' fist slammed on the table.Cornelius: SAVAGES! They're all savages!
- Moses in the Bulrushes: The unassuming chimp baby that was the first to be born in a circus sitting in a cage, saying "Mama".
- Next Sunday A.D.: Filmed in 1971, takes place in 1973, a year after Taylor's spaceship in the first movie originally left the Earth.
- Nice Job Breaking It, Herod: Hasslein's obsession with killing Zira's baby merely ensures that nobody notices Zira had switched babies with another chimp mother at Armando's circus. Openly referenced in the movie by the President, played by William Windom, who refuses at first to sign off on aborting Zira's pregnancy, and directly cites Herod's murder of innocent children as a reason.
- Prequel in the Lost Age: From the apes' point of view, it's this.
- Reasonable Authority Figure: The President.
- Red Shirt: Dr. Milo — although in fairness, his death wasn't actually meant to happen until much later in the film. The actor had trouble working with the makeup prosthetics however, and the character's death was brought forward.
- Rule of Symbolism: The series started having racial conflicts overtones, and in this one also had Biblical parallels (it's even lampshaded with a line mentioning Herod).
- Sequel Hook: The ending scene was meant to simply connect this movie to the future. Executive Meddling led to more movies. After his experience being forced to write this sequel after Beneath (which was written with as final a Downer Ending as could be done), screenwriter Paul Dehn wrote the ending of Escape as both a link to the future storyarc and with enough wiggle room to squeeze in another movie if the studio wanted it.
- Well-Intentioned Extremist: Dr. Otto Hasslein; he believes the only way to prevent the fall of mankind (and by extension, the destruction of Earth) is to kill the apes and their child.