Planet of the Apes series. Battle for the Planet of the Apes (1973) is undoubtedly the weakest of the early entries. It's not bad on a Superman IV or Batman & Robin level, but it's a step down in quality from the earlier films.
The problems mostly stem from 20th Century Fox's decision to cut corners and do the movie as cheaply as possible. We get stock footage from two of the earlier movies, costumes are reused (suggesting that ape fashion will not change over two thousand years), many of the ape masks look fake, and some shots seem to be missing entirely, resulting in a lot of confusing and jarring transitions. In one case, we see run Caesar (Roddy McDowell) send his son Cornelius (Bobby Porter) off to play, and then the film jumps to Caesar in his home and his wife Lisa (Natalie Trundy, who, like McDowell, appeared in four of the Apes movies but who has the distinction of having played an ape, a mutant, and a human scientist) tells him to say good night to their son, and there's Cornelius lying in bed.
Most disappointingly, Battle comes off less as the epic capper to a venerable franchise than it does a restricted, television-level affair. The titular battle between the apes and mutants, far from being the titanic clash for control of the world as the title seems to promise, is a rather limited skirmish with a few dozen combatants on each side. The scope is very confined, the action scenes aren't especially memorable, and the world seems very small. The mutants live in a dank basement, and the apes and normal humans mostly mill about outside with only the occasional hut or set.
Conquest of the Planet of the Apes, in a matter of a few short years has apparently taught all these jungle chimps, gorillas, and orangutans the power of speech and formed a new society in which he is king, humans are second-class citizens (still capable of talking), and the apes have advanced to the point where they make jokes about time travel paradoxes. The film, except for the beginning and the end (which are set in the far future with a bored-sounding John Huston as the Lawgiver), takes place after a nuclear war, but I was unclear whether that was mankind's response to the simian revolt or some other conflict.
Still, if there's one thing to admire in the Planet of the Apes is that they were never short on ideas or imagination. 20th Century Fox may have chipped away at the budgets, but not one of these early films can be described as generic or uninteresting, and that includes Battle. There's still plenty to enjoy and discuss if you're willing to overlook the film's aforementioned weaknesses.
The Planet of the Apes saga was, prior to this entry, dark and pessimistic, a warning for where mankind was heading if humans did not change their ways. Battle is the most hopeful of entries, suggesting cooperation between the two warring sides, ape and man, is achievable; the end of the world, at the hands of Taylor and the atomic bomb, may be avoided if the humans and apes treat each other as equals, and Battle shows Caesar and company's efforts to do just that. Instead of a crumbling Statue of Liberty or a bomb going off, the movie closes with the ape Lawgiver teaching both ape and human children while a statue of Caesar sheds a tear.
In contrast, the mutants, now led by Governor Kolp (Severn Darden), cling to the old ways and seek to reassert their power. Sick, dying, and malformed by nuclear radiation with so much of the world already devastated by conflict, all they can think to do is to inflict more violence and destruction. Kolp has something of a conscience in the form of Mendez (Paul Stevens), who tries every step of the way to talk sense into him, but Kolp disregards him, and when he learns of the ape settlement, he becomes determined to destroy it. The mutant nature is reflected in a neat visual touch: Kolp's armada includes a re-purposed school bus. Instead of transporting children to school, it carries armed mutants to battle, hinting at man's self-destructive tendencies at the expense of the future.
The other villain of the piece is General Aldo (Claude Aikins), a gorilla who seeks to usurp Caesar and wipe out the humans. Aldo's actions forces Caesar to wrestle with tough moral questions. Ape doctrine commands that "Ape shall never kill ape," and yet, Aldo commits murder by killing Cornelius, cutting a branch the boy is on when he overhears the gorilla's plan, sending Caesar into despair and grief.
When Caesar learns who the murderer is, he in turn kills Aldo, knocking him from a tree, but he asks afterward if one murder can avenge another. The apes are still a new society in Battle and haven't had long to deal with these hard questions. They are somewhat naive, innocent almost. When the first ape murderer is exposed, MacDonald points out "they've finally joined the human race."