There’s a scene in Dawn of the Planet of the Apes when, with the man vs. ape conflict quieted for the moment, an ape sits on a bed in an attic and watches a video from a time long gone, when his life was simple and happy. A wistful smile crosses the ape’s weary face and his eyes shimmer with regret and longing. It’s a brief but rather beautiful scene, and rather startling in its effectiveness, especially considering this is a motion-capture creation in a science-fiction thriller who is eliciting such complex and genuine emotion.

That is one of the great strengths of this sequel to 2011’s smart, surprisingly chilling franchise reboot. The apes, now fully sentient and able to speak in halting English, have become full-blooded characters, with wants and worries and resentments, just like us humans. Following their big battle on the Golden Gate Bridge at the end of Rise of the Planet of the Apes, they have retreated into the Muir Woods and formed a primitive but utopian society, living off the land and raising families and passing beliefs and traditions down through newly forming generations. It’s all very inspiring and, oddly enough, believable. Director Matt Reeves and his screenwriters have done a prodigious job of avoiding the many opportunities a story like this provides to get campy, and have instead made something grave and classically tinged. A stirring, thoughtful film that doesn’t skimp on suspense and excitement, Dawn of the Planet of the Apes is a high point of this, or any other, summer season.

Taking place 10 years after the events of the first film, Dawn presents us with an ape world that’s flourishing and a human world that lies in ruin. An epidemic has reduced the human population to a bedraggled contingent of the genetically immune, and the stage seems set for the apes to finally make the planet their own. But, humans being humans, the few that remain are determined to rebuild and reclaim what’s been lost. That, of course, inevitably means encroaching on the fledgling society the apes have established, which is when the problems begin.

Led by the ape-loyal but human-sympathetic Caesar (the brilliant Andy Serkis), the apes warily agree, after a violent first encounter, to let a group of survivors, including Jason Clarke’s good-hearted Malcolm, his wife Ellie (Keri Russell), and his son Alexander (Kodi Smit-McPhee), enter their territory to reactivate a hydroelectric dam that will restore power to San Francisco. Though tensions are high, human and ape slowly learn to trust one another. But sadly it’s only a tentative peace, and before long, owing to a cruel betrayal and a tragic misunderstanding, man and ape are pitted against each other in an epic battle for dominance. We always knew it was coming to this, and yet the film still manages to surprise and intrigue.

That is perhaps the most interesting thing about this prequel/reboot franchise. It’s right there in the title that this planet will at some point go to the apes, and yet knowing the grim end doesn’t lessen the films’ impact. Really, it only heightens it, as the story becomes less a tingly bit of genetics paranoia and more a grand and somber look at the inevitability of conflict. This is heady, dark stuff for a summertime tent-pole picture to be mulling over, and yet this film handles it not only with admirable sincerity, but with an intelligence and dexterity rarely seen in mainstream, big-budget movies these days. This is not exactly a profound film, but it addresses its weighty themes with striking clarity and narrative nuance.

Neither every ape nor every human wants to go to war, and most of our conflicted heroes spend their time trying to stave off that inexorable conclusion. So we are caught in a fascinating state of ambivalence, rooting for neither side absolutely. That Reeves is able to explore that murky gray area while still keeping things propulsive and action-packed is testament to his subtle, unpretentious skill. There are a few moments of thrilling artistic flair to be found in the film—a long and bracing tracking shot during an ape raid of a downtown building, a panoramic look at a melee from the viewpoint of a tank—but Reeves spends most of his energy trying to tell a muscular and straightforward story. He more than succeeds, making a picture that is old-fashioned in its structure but modern in its dazzling execution.

What the film is able to do with the apes, motion-captured from performances by Serkis, Judy Greer, Toby Kebbell, and others, is astounding. The apes have such tangible presence that we almost immediately forget that they aren’t, well, real. This is not a film that asks that we sit in giddy awe of its technical marvels, just that we thoroughly believe them. It’s a refreshingly practical approach to all that computer technology allows. The FX wizardry emboldens the story, makes it possible and visceral, but never overwhelms it. Compared to something like Transformers, with all its eyeball-scorching decadence, Dawn is almost stoic. It’s full of wonders, just not the kind with big red arrows pointing right at them.

Smart but earnest, dark but never cynical, Dawn of the Planet of the Apes is the rare sequel that improves upon its predecessor—it’s bigger, meatier, bolder—and the extremely rare zillionth installment of a mythology that makes a compelling case for the whole thing’s existence. A grim look at man’s inhumanity to man (and, yes, ape), Dawn does not shy away from the doom to come, and yet it’s ultimately a hopeful film. If one summer studio action movie can be this good, surely others can too.