20th Century Fox fast-tracked a [lower-budgeted] sequel to its very successful sci fi classic PLANET OF THE APES, thus ushering in the relatively new concept of movie franchises. As a kid, I didn't care for this entry so much, but revisiting it today, I had a blast with it! Charlton Heston didn't want to reprise his role as Taylor, the astronaut from the original film who crash-landed into Earth's future where intelligent APES rule the roost, but he was coerced into taking an "extended cameo" part that bookends the beginning and end of the film. Early on, Heston vanishes into thin air while exploring the Forbidden Zone areas with his curvy squeeze Nova. James Franciscus [who is pretty much decked out as a Heston clone] takes the title role in this entry, playing an astronaut from Earth's past that is searching for Heston's character. What we have here, essentially, is a remake of the first movie as Fransciscus searches for Heston and encounters the APE society. Early on [in a "movie coincidence" hard to overlook] Franciscus hooks up with Nova, Heston's sultry gal playmate, once again played by the delicious to ogle Linda Harrison. Together, they are captured by the Apes, escape, and run into the Forbidden Zone while searching for Taylor. Hiding from the pursuing Apes in underground caves, this flick takes a wild detour from the original when Franciscus and Nova encounter human mutants who worship a large nuclear bomb in church-like ceremonies! Taylor is found, now a prisoner of the mutants, and the Apes track everyone down in the caverns where everyone is pitted against each other in an end fight to the death! This film has one of the bleakest endings ever for a Hollywood movie, not seen again until, perhaps, the end of TERMINATOR 3: RISE OF THE MACHINES. I found this APES entry to be well-paced, action-packed, and variably different from the original film in the second half. Composer Leonard Rosenman delivers an awesome soundtrack in the fine traditions of Jerry Goldsmith, and I came away from this view thinking this movie has been severely underrated. Worth another look, directed by Ted Post, who would go on to helm Dirty Harry's excellent sequel, MAGNUM FORCE.