"Give praise to the Almighty Bomb and the Holy Fallout."
Psychic atomic bomb worshippers are a minority group that have been less that adequately represented in film history. Beneath the Planet of the Apes attempts to atone for this injustice.
Originally released in 1970, the first sequel to the original Planet of the Apes was more than just a rehashing of the plot of the original, which is something all too common in the modern day sequel. Instead, this film is a masked piece of social commentary on the Cold War released at the point when people were beginning to accept that the 60s were over. This is a movie that, if you pay close attention, you will pick up many references to racial issues, the politics behind war, and thinly veiled references to the concept of nuclear weapons being necessary "weapons of peace." If you don't pay careful attention, you'll enjoy a playful, enjoyable romp.
The story picks up as the first movie ends, including footage of the climax of Planet of the Apes in the opening sequences. NASA is bothered somewhat by the disappearance of the original astronauts, including Charlton Heston, who vanished and found their way to the planet of the apes. They dispatch a new team, who also crash, with but one survivor. He just happens to look a bit like Heston for some reason. Genetic coding may have something to do with surviving space crashes.
There is the expected reaction to the apes who rule this world, but then we are led into the Forbidden Zone, an underground commune of the aforementioned psychic bomb worshippers which turns out to be the New York City subway system, complete with Grand Central Station. Taylor, the character from the original played by Heston, is said to have disappeared to this zone and so Brent, the new astronaut, goes there to seek him out.
These psychic bomb worshippers have the ability to create telepathic illusions which are powerful enough to make men disappear. They often state they are peaceful, but that in order to survive they cause their enemies to "kill each other." However, they themselves are susceptible to being killed by guns wielded by apes.
Oh, by the way, they are storing this golden nuclear weapon inside what used to be St. Patrick's Cathedral.