The Planet of the Apes series takes an angry turn in the fourth entry, Conquest of the Planet of the Apes.
The story begins about 20 years in the future, after a world epidemic has destroyed all dogs. People first had turned to apes as pets, but because of their intelligence the apes have become servants under civil regulation of computer-age overseer Don Murray. Into this milieu comes traveling circus operator Ricardo Montalban who, at the end of the prior film, had concealed the nearly-human offspring of the murdered Roddy McDowall and Kim Hunter. McDowall now has shifted to the role of his son.
In the new world, McDowall has to Uncle-Tom his way through the prevailing slave environment, until Murray’s inexorable search for the long-missing ape-human child leads to Montalban’s death under torture-grilling by Severn Darden. McDowall then organizes a bloody revolt which occupies the last third of the film.