In 2029, aboard the United States Air Force space station Oberon, Leo Davidson works closely with primates who are trained for space missions. His favorite simian co-worker is a chimpanzee named Pericles. With a deadly electromagnetic storm approaching the station, a small space pod piloted by Pericles is used to probe the storm. Pericles's pod heads into the storm and disappears. Leo takes a second pod and goes into a pursuit search for Pericles. Entering the storm, Leo loses contact with the Oberon and, in 5021 A.D., crashes on a planet called Ashlar. He discovers that the world is ruled by humanoid apes who speak English, use domesticated horses for transportation, and treat human beings as slaves.
Leo comes across a female chimpanzee named Ari, who protests the awful treatment humans receive. Ari decides to buy Leo and a female slave named Daena to have them work as servants in the house of her father, Senator Sandar. Leo escapes his cage and frees other humans. Limbo, a slave trader in captured humans, sees them but is taken prisoner to ensure his silence. The human-hating General Thade and his junior, Colonel Attar, march ape warriors in pursuit of the humans. Leo discovers Calima, the forbidden, but holy temple of "Semos", the first ape whom the apes revere as a god.
Calima turns out to be the remains of the Oberon which had crashed on the planet's surface and now looks ancient (the name Calima coming from the sign "CAution LIve aniMAls", the relevant letters being the only ones not covered in dust). According to the computer logs, the station has been there for thousands of years. Leo deduces that when he entered the vortex, he was pushed forward in time, while the Oberon, searching after him, was not, crashing on the planet long before he did.
The Oberon's log reveals that the apes on board, led by Semos, organized a mutiny and took control of the vessel after it crashed. The human and ape survivors of the struggle left the ship and their descendants are the people Leo has encountered since landing. The apes arrive and attack the humans who have gathered to see Leo, although he is able to even the odds when he uses the Oberon's last fragments of fuel to fire a final blast at the first wave of apes. The battle is halted as a familiar vehicle descends from the sky and is identified immediately by Leo. The pod is piloted by Pericles, the chimp astronaut. Pericles was pushed forward in time as Leo was, and had just now found his way to the planet, the electromagnetic storm actually releasing people from it in an opposite direction in time to their entrance. When Pericles lands and the pod opens, the apes interpret his arrival as the return of Semos. They bow, and hostilities between humans and apes suddenly cease.
Pericles runs into the wreck of the Oberon and Leo runs after him, followed by General Thade. Thade and Leo fight. Pericles tries to help Leo, but Thade throws him hard against a wall. Thade takes Leo's gun from him and tries to fire it at Leo. Leo sees that Thade is within the pilot's deck and closes the automatic door, trapping Thade inside. Thade fires the gun repeatedly at the door but the ricochets create sparks that scare Thade, who huddles under a control panel. Leo decides to escape Ashlar and return to Earth. He gives Pericles to Ari, who promises to look after him. He says goodbye and kisses Ari and Daena. Leo climbs aboard Pericles's undamaged pod and travels back in time through the same electromagnetic storm, and crashes in Washington, D.C. on Earth. He looks up at what appears to be the Lincoln Memorial, only to find that it is now a monument memorializing General Thade. Leo is descended upon by a swarm of police officers, firefighters, and news reporters, all of whom are apes.
Mark Wahlberg as Captain Leo Davidson
Tim Roth as General Thade
Helena Bonham Carter as Ari
Michael Clarke Duncan as Colonel Attar
Estella Warren as Daena
Kris Kristofferson as Karubi
Cary-Hiroyuki Tagawa as General Krull
Paul Giamatti as Limbo
Jonah and Jacob (both uncredited) as Pericles
other roles include David Warner (Senator Sandar), Lisa Marie (Nova), Erick Avari (Tival), Luke Eberl (Birn), Evan Parke (Gunnar), Glenn Shadix (Senator Nado), Freda Foh Shen (Bon), Chris Ellis (Lt. Karl Vasich), Anne Ramsay (Lt. Col. Grace Alexander), Kam Heskin (Friend at Leo's Party), and Melody Perkins (Friend at Leo's Party).
There are also cameo appearances by Charlton Heston (uncredited) as Zaius, Thade's father, and Linda Harrison (the woman in the cart).
The sixth film in the Planet of the Apes franchise, loosely adapted from Pierre Boulle's 1963 novel of the same name and the 1968 film version