Planet of the Apes movie with the chimp couple Zira (Kim Hunter) and Cornelius (Roddy McDowell returning to the series) as the main protagonists. Beneath the Planet of the Apes ended with the destruction of Earth, and while that was done by the filmmakers with the intention of finishing the series, time travel has a way offering a way out of narrative dead ends.
Escape from the Planet of the Apes inverts the paradigm we'd seen in the series so far. Instead of a modern-day human traveling to a future Earth where intelligent simians ruled primitive humans, Escape features a trio of intelligent apes - Zira, Cornelius, and Milo (Sal Mineo) - escaping the planet's destruction by journeying to the past, specifically 20th century Los Angeles, where humans still sit atop the evolutionary food chain.
This setup takes a little effort to accept. We're to believe these apes, previously amazed by a paper airplane, somehow salvaged Taylor's ship from a lake, repaired it, and used it to escape before the world ended and prior to the start of this movie. Also some of the back story, about how the apes rose to dominance in the future, is ret-conned by Cornelius, who shares a story about how apes revolted against human masters after a plague wiped out dogs and cats and humans took apes as pets. The whole plot of the original was Taylor and Cornelius working to prove humans came before apes, counter to the dogma of the Lawgiver. If the ancient scrolls already revealed humans used to be smart, why did Zaius work so hard to cover that up? Cornelius mentions the scrolls were secret, but when did he learn this when his evidence was based on archeological artifacts?
Maybe if Beneath the Planet of the Apes had been done in the way I suggested, these inconsistencies could have been addressed. No matter, once you get past that suspension of disbelief, Escape from the Planet of the Apes gives the series new life and leaves an open ending allowing for further adventures, albeit after a grim, shocking, and heartbreaking demise for the two chimps we've grown to love over three movies.
This leads to the second act in which Zira and Cornelius become media sensations, and the film becomes more of a fish-out-of-water comedy as the apes tour the city, check into a hotel, visit a museum, get new wardrobes, and become celebrities. It's pretty silly, but how else would you expect talking apes to received in 1970's Los Angeles? Their personalities shine through with Zira in particularly being, to use the movie's term, "uppity" and Cornelius getting his share of zingers. When the hotel clerk asks for an address, Cornelius shrugs and says, "The zoo." Zira also speaks to a women's group about marriage while Cornelius attends a boxing match, which he describes as "beastly." The idea that humans make violence entertainment upsets him.
The previous entries in the series illustrated the dangers of religious fundamentalism and how dogmatic beliefs can be used to justify wars of conquest. Greed, hunger for power, and hypocrisy were the great sins. Escape focuses on distrust and fear of "the other," people (or in this case apes) who are different. Over these first three movies, apes and humans discover the other is capable of thought, reason, and emotions, but instead of empathizing with each other and finding common ground, they resort to conflict, each fearful the other will prove dominant.
If there's one thing the Apes has been good at, it's its villains, and Dr. Hasslein fits well with the likes of Dr. Zaius and General Ursus in that he believes he is perfectly justified in his actions, and it's not hard to understand why. Knowing where Zira and Cornelius come from, and what that future means to the survival of the human race and the planet, it's understandable he takes extreme action. The future, with humans reduced to brutish animals hunted down and experimented on by apes, is something he tries to stop.
But Hasslein's drastic actions fail. While Cornelius and Zira are killed, their child survives, and as we see in this film's followup, Conquest of the Planet of Apes, that ape-child grows up to lead the very revolution Hasslein tried to prevent, only it happens a couple of centuries earlier than originally foretold. His actions only accelerated the future ape revolt. Violence begets violence.