Grade: B

Though technically astonishing, the second picture in the reboot of the “Planet of the Apes” franchise suffers from the same difficulty that plagued its predecessor, “Rise of the Planet of the Apes”—namely, that the original series of movies, released back in the late sixties and seventies, predetermine the outcome. The 1968 “Planet” portrayed an earth taken over by intelligent simians, with humans a downtrodden, servile class, and its successors, on both the big and small screens, were based on that idea (as was Tim Burton’s misbegotten remake). “Rise” and now “Dawn” amount to prequels that essentially spell out how earth got to that condition. So the ending is, as it were, as unchangeable as was the case with the second “Star Wars” trilogy, and the only question is how cleverly the filmmakers can get there. It’s not an easy nut to crack—the Lucas crew certainly botched it. Happily, things go better in this case. “Rise” was good, and “Dawn” is a worthy continuation of it.

That’s not to say that in narrative terms “Dawn” isn’t pretty thin. “Rise” covered the experiments that resulted in Caesar (acted by the incomparable Andy Serkis through motion-capture wizardry) undergoing abrupt intellectual evolution that allowed him to lead a successful rebellion against the monkeys’ human captors. “Dawn” starts ten years later. Under Caesar’s benevolent rule, the simians have established a community in the forests outside San Francisco, building harmony among themselves and raising happy families.

Humankind hasn’t fared nearly as well. As a result of an epidemic initiated by the very serum that brought about Caesar’s development, most of mankind has died off. One of the batches of survivors lives in the ruins of the City by the Bay, led by an owlish fellow named Dreyfus (Gary Oldman). But since their nuclear power source is drying up, the hope of keeping the lights on depends on whether one of Dreyfus’s colleagues, Malcolm (Jason Clarke), can get a defunct hydroelectric dam outside the city up and running again. He, his wife Ellie (Keri Russell), their son Alex (Kodi Smit-McPhee) and a few others have traipsed off to the dam—only to find themselves in Caesar’s domain. When hothead human Carver (Kirk Acevedo) shoots one of the young apes, Caesar orders the humans to depart—much to the distress of his bellicose second-in-command Koba (Toby Kebbell), who would prefer to slaughter the interlopers on the spot.

The desperate Malcolm comes back with hat in hand, and the peace-loving Caesar allows the humans to proceed in their work, with the proviso that they bring no guns with them. Unfortunately Carver breaks that agreement, and though Malcolm gets the dam working again, the breach sets Koba off on a mission to unseat Caesar and undertake an assault on the humans. Much mayhem ensues, and though Caesar and Malcolm work furiously to defuse the situation (reaching a human-simian understanding between them in the process), they part in the realization than a human-ape war has in effect begun whether they like it or not. Cue work on the sequel.

In fact, “Dawn” gives one the feeling that the makers are effectively biding time until that third installment; it’s like an appetizer to a meal that’s still being prepared. In effect the picture is little more than a typical “clash of civilizations” tale that once might have involved cavalry and Native Americans confronting one another, with leaders on both sides unable to prevent violence even though they’ve come to understand that they have much in common and amity would benefit everyone. It even provides a character that can learn the lesson the conflict brings: Caesar’s young son River (Nick Thurston), torn between his father’s rationality and Koba’s mindless hatred, who must eventually choose between them.

If the premise is familiar, however, it’s nevertheless well realized by director Matt Reeves (“Cloverfield”) and his behind-the-camera team of production designer James Chinlund, art director Aaron Naaman Marshall, set decorator Amanda Moss Serino, cinematographer Michael Seresin and the Weta Digital effects army headed by Joe Letteri and Dan Lemmon. The meshing of live-action and motion-capture imagery is practically seamless—it will take repeated viewings with the pause button to detect the flaws—and the result, especially in the massed battle sequences, is eye-popping, especially with the added effect of subtly-used 3D. Michael Giacchino’s score, which occasionally employs choral elements, is vigorously supportive without overshadowing the visuals—which would be difficult to do under any circumstances.

As for the characters, the humans are a bland bunch, led by the nondescript Clarke, the equally unmemorable Russell and a wasted Oldman (certainly a good deal of his work must have been left on the cutting-room floor by editors William Hoy and Stan Salfas); only Acevedo stands out among them, and not for a good reason—he really chews the scenery. But it’s the monkeys that matter, and here the film delivers. Serkis once again proves a marvelous mime of simian movement, bringing genuine depth to Caesar, and Kebbell is nearly as impressive as the ferocious Koba. Also notable are Thurston and Karin Konoval as the wise old orangutan Maurice, whose sad-eyed observation of the collapse of the ape community is penetratingly caught.

“Dawn of the Planet of the Apes” is no feel-good bit of summer fluff—it’s another vision of a dystopian future (the flavor of the cinematic week) and one that’s headed, as we all know, for an outcome in which mankind will not be victorious—and it casts an unremittingly bleak, somber atmosphere, marked by visuals that, while impressively, are dark and forbidding. And it inevitably has a predictable feel, dictated by its adherence to a plot playbook established long ago. But just as Rupert Wyatt did with its immediate predecessor, Reeves and his colleagues—especially Serkis—have managed to give the material as much freshness as one could reasonably hope for. The result is a canny continuation of the saga that delivers mood and action in approximately equal measure to compensate for a threadbare plot.