I should start out by saying that I am aware that the actual title is Beneath THE Planet of the Apes. However, given that the original film was called Planet of the Apes, not THE Planet of the Apes, I feel I can get away with calling it Beneath Planet of the Apes. Moreover, it's just a personal preference--I like saying Beneath Planet of the Apes, Escape from Planet of the Apes, etc. I even prefer Rise of Planet of the Apes, but now I digress.
Planet of the Apes (the original) turned out to be not only a critical hit but an immensely financially successful one. However, the film ended with one of the greatest endings in film history, so how could a sequel ever be mounted that could top it, or even come close to matching it. Beneath Planet of the Apes doesn't do either, but it manages to create a somewhat logical story to tie it with the original.
We begin where we left off in Planet of the Apes. Taylor (Charlton Heston) and Nova (Linda Harrison) ride out further into the Forbidden Zone. A short while later, we see a new astronaut has crashed in the desert. We learn that this astronaut, Brent (James Franciscus), was part of a rescue operation for the first astronauts, but now he's the only survivor. Brent comes across Nova, who now is alone. Through her memories, we learn what happened to Taylor: they encountered strange visions of fire and earthquakes until Taylor simply vanishes. Having been told by Taylor that if anything should happen to him she should go to sympathetic chimpanzee Dr. Zira (Kim Hunter), Nova takes Brent back to the Ape City.
Here, the gorilla General Ursus (James Gregory) bullies the apes to go into the Forbidden Zone on a military expedition/extermination campaign. The brutal gorillas, who appear to be the majority of the Simian world, eagerly push on for war, while the chimpanzees and orangutans go along with this, despite the misgivings of orangutan elder Dr. Zaius (Maurice Evans). Only one chimpanzee makes her objections clear: Zira. It is only under intense pressure from her now-husband Cornelius (David Watson, filling in for Roddy McDowall) that she gives her consent (although she makes it clear it is under pressure). Zira and Cornelius find Nova and Brent, and urge them to find Taylor. However, they are captured by the gorillas but manage to escape into the Forbidden Zone.
Deep beneath the planet of the apes, Brent discovers the ruins of a lost world and inside this lost city lives a group of humans who are able to project false imagery and both control and read the minds of others. Brent discovers to his horror that these humans are mutants, disfigured beings underneath their masks, and more horrifying, that they worship a nuclear weapon within their cathedral. The apes, under the belligerent Ursus and with Dr. Zaius accompanying him, go into the Forbidden Zone, where they encounter the mutants. Soon a battle between the mutant's mind control and the apes' weapons begins.
Brent and Taylor finally meet, but under the mind control of the mutants, begin to fight to the death until Nova, in her horror, finally speaks. The surprise of a human voice distracts the mutant enough to let Taylor and Brent kill him, but now with the apes invading their world, the mutants decide that the Alpha & Omega bomb is to be used. Taylor and Brent go the cathedral in an effort to stop the bomb, but in the fighting, both are fatally wounded, but not before Taylor and Zaius have one last confrontation.
Beneath Planet of the Apes was clearly an effort to cash in on the phenomenal success of the original, and here is where the film fails. The shock of the first one is gone, especially from Franciscus' performance. When he comes upon Ape City, he doesn't look as shocked as one would think someone coming upon a world where apes speak would look like. It almost looks like he's seen the first movie, so he knows what he's in for. Whatever flaws people find in Heston's performance from the original, he maintained a righteous fury that propelled Taylor. Brent looks mostly curious, perhaps slightly puzzled, as to how the planet of the apes came to be, but he never communicates the total shock and/or horror of his discovery.
It isn't just Franciscus' one-note performance. The script by Paul Dehn (from a story by Dehn and Mort Abrahams) almost plays as a parody of Planet of the Apes. When Brent is studying the remains of the lost world, he says, "My God, did we do it? Did we finally, really do it?" This is almost word for word Taylor's final comments at the end of Planet of the Apes, and it is stretching it a bit to think Taylor and Brent would use almost the same words. To my mind, it's almost lazy scriptwriting.
The actual plot of Beneath Planet of the Apes has great promise but never goes far enough. For example, having a secret human world underneath the ape world has possibilities, but what we end up with are curious, almost comic, scenes of people merely moving their heads with accompanying chirps to signal they are "speaking" with Brent. It is a lot to ask of Franciscus as Brent to basically carry a one-sided conversation and it's a puzzle as to why producers Abrahams and Arthur P. Jacobs decided to have long scenes where Brent has to answer unasked questions vocally--I figure it would have been too ridiculous to have him answer in kind, which would have turned Beneath Planet of the Apes into a silent movie.
One idea the film has (about reckless and dangerous military exercises) could also have worked in trying to make the film as topical as its predecessor. However, while Planet of the Apes was more subtle in its approach, Beneath Planet of the Apes was almost blatant: you can't have young chimpanzee war protesters with pickets about 'no war' without making it obvious it's suppose to be anti-Vietnam War protesters. Another odd choice was when Ursus in his war speech declared that he didn't hate the human 'because his skin is white'. Can we say blatant?
Finally, if director Ted Post is going to spend time showing us the gorilla training, then make the escape from the gorillas be more exciting instead of simply having Zira help them out. Curiously, Zira and Cornelius played a small role in Beneath Planet of the Apes, and while Watson did the best he could to fill in for McDowall, it wasn't hard to see it wasn't the same Cornelius. However, Hunter was the best as the principled Zira, the only chimp who saw through Ursus' bullying to get them into a needless war. Perhaps if more time had been spent on the politics of war, Beneath Planet of the Apes would have had the topical nature it was so desperately seeking.
Curiously (or sadly) the make-up work was both good (when the mutants reveal themselves it was quite effective) and bad (in the ape gathering it was clear some were wearing ill-fitting masks). Zaius' final words to Taylor are also quite effective (and sadly ring true): "Man is evil, capable of nothing but destruction". It would have worked better in this final confrontation to have had a better battle between man and ape (and to give Heston more to do, although he agreed to be in the sequel only if it were the end for his character and to have as small an appearance as possible).
This isn't to say Beneath Planet of the Apes isn't entertaining, but it really is a pale shadow of the original. Granted, it appears there was never any real thought to a sequel until after Planet of the Apes became the success it ended up being. Therefore, the makers spun the best story they could--but it just wasn't all that good. In the world of the Planet of the Apes franchise, it certainly lived up to the title--it really was beneath Planet of the Apes.
Next Planet of the Apes Film: Escape from Planet of the Apes