The latest sequel to the rebooted Planet of the Apes franchise, Kingdom of the Planet of the Apes, isn’t good. Its wall-to-wall CGI visuals are largely uninspired, a demoralizing comedown from the thrilling look of the last two Apes films. The characters are weak compared to Caesar, Koba, Maurice, and the other main apes of the franchise so far, which is partly why the narrative takes forever to get any real traction. And the pace set by director Wes Ball of the Maze Runner movies, taking over from Rupert Wyatt and Matt Reeves who guided the earlier Apes reboot films, is glacial.

But the movie’s making a ton of money. Audiences worldwide haven’t lost their affection for the Apes.

And in spite of my griping, I keep turning up for these rebooted Apes movies too, though the last one I really liked was the second one, Dawn of the Planet of the Apes (2014). In general, I’m finding unimaginative, CGI-heavy blockbusters ever more boring to look at, and their slow, remedial, film-viewing-for-dummies narratives are so overlong, they’ve become a literal pain in the ass.

Nevertheless, somehow I know that when the next Apes sequel comes out, I’ll be right there in the theater watching that one too. Very addictive, these movies, though the quality varies tremendously.

Kingdom of the Planet of the Apes is set “many generations” after the death of Caesar, the enlightened figure (played by Andy Serkis) who founded a stable ape society. His maxims are still quoted (“Ape must not kill ape”) but as we’ll see, no longer followed. Humans have been vanquished and live as lowly scavengers scuttling away in the underbrush.

The plot centers on a young chimp named Noa (Owen Teague) of the peaceful Eagle Clan — apes that train birds of prey to hunt for them. His main concern is a quest with his two best friends, each seeking an egg from the highest wild eagle’s nest in order to go through a coming-of-age “bonding ceremony” with the fledglings they’ll train.

But that night, the Eagle Clan’s forest idyll is overrun by militarized gorillas on horseback wielding weapons that generate an electric current, a literally stunning technological advance. The gorilla soldiers then abduct and enslave any chimps they haven’t killed.

Noa sets out in pursuit to rescue the survivors. Along the way he’s joined by Raka (Peter Macon), an erudite orangutan still keeping faith with Caesar’s teachings, and Mae (Freya Allan), a vulnerable-looking human starving alone in the forest who seems to have no language, a common condition of the human species in an ape-dominant world. Ultimately it will become clear that she’s also seeking her lost community, and both she and Noa will have to journey to the kingdom of the brutal bonobo ruler Proximus Caesar (Kevin Durand) to find those they’ve lost.

Fortunately for viewers trying to stay awake, Proximus is the charismatic old monarch of a harsh, seaside, cliff-dwelling realm buffeted by waves that really fills the eye. He’s obsessed with his quest to open an iron fortress where all that remains of human history and human technology is locked away, presuming it will guarantee his kingdom’s supremacy even after his death. He sends his soldiers out on slave-hunting raids to give greater muscle to the daily attempts to pull open the iron doors.

“Maybe tomorrow — stronger,” he says with an almost touching faith when the day’s big pull, relying on groaning slaves and sweating horses and whip-cracking gorillas, fails again.

Proximus is a harsh ruler with an urgent desire for any kind of knowledge that can help him wield power over the long term. He keeps a human librarian, tutor, and advisor to teach him human history. It’s a kind of Anna and the King of Siam scenario, only with William H. Macy, of all actors, as the unlikely “Anna” figure. He’s called Trevathan, and he’s a seedy opportunist who advises Noa to make the most of his good luck when Proximus recognizes Noa as a clever ape.

“I have use for clever apes,” says Proximus, and it’s a darn shame that the film didn’t cut some of the earlier plot so it could’ve dwelled here for a while. Proximus is a compelling character, and Noa could’ve remained in his kingdom for some time, torn between understanding and sharing the king’s quest for knowledge, and despising and rebelling against his savage autocracy.

It’s also during this last and most interesting third of the film that we find out Mae not only has language, she has a pro-human agenda that’s going to make her a dicey ally in Noa’s attempts to free himself and his clan from Proximus’s rule.

Whether or not to trust humans is always a burning question in Apes films, and the ultimate answer is always the same: no. But cultural amnesia and lost or hidden aspects of shared ape-human history are a fundamental part of the experience in these movies. The human protagonist makes the shocking discovery that the planet of the apes is actually Earth after the conquest of the humans, and the ape protagonist finds that ape supremacy, always increasingly authoritarian and charting a familiar path to authoritarian self-destruction, relies on suppressed links to human knowledge and technology. The tangled history of the primates is so demoralizing, it’s always hidden away or forgotten again, and tentative feints at trying to form ape-human allegiances are always doomed.

Which is what makes these films so compulsively watchable — their fundamental despair at the arc of primate history, with humans as the craziest and most destructive of the primates. This arc doesn’t bend toward justice. There’s no way to make an Apes film without engaging in the furious social critique that began with the still-startling first film, the 1968 Planet of the Apes, with its scathing satirical take on human ideology informing ape behaviors.

Kingdom of the Planet of the Apes is a relatively weak link in the franchise chain, but the premise of the film series is so strong, we’ll all go anyway, and hope for better things next time.