In the opening credits of Zack Snyder’s dour superhero movie Watchmen, there’s a montage showing a generation of superheroes as they travel through decades of American history, participating—triumphantly, tragically—in major events and riding undulating waves of public opinion. It’s a brilliant bit of world-establishing, and a tingling evocation of something so many comic books capture, and yet so few of the movies based on them do: a true sense of how these icons—vessels of our squarest hopes and most persistent cultural paranoias—have been mapped onto the American psyche, both reflecting and absorbing us. It’s a downright moving sequence, and makes one of the most convincing cases for translating superhero comics into film that I’ve yet seen.

Of course, then the rest of the movie happens and things get messy, Watchmen clunking down the well of cultural memory and disappearing into the dark. Zack Snyder’s new superhero film, Batman v Superman: Dawn of Justice, seems, unfortunately, destined for the same fate.

Like in Watchmen’s beginning moments, this new film-as-brand-extension has a stretch, arriving somewhere in the middle this time, that is captivating, persuasive, resonant. In those scenes, we watch a society (American society, in particular) grapple with the realities, and surrealities, of this newly arrived alien called Superman. He’s just defended Metropolis, and the world, from General Zod and his army, but Metropolis has been ravaged in the process, at the cost of thousands of lives. The opening of Batman v Superman brings us back to that city-destroying battle, seen at the end of Snyder’s Man of Steel, and shows us the perspective of a man on the ground, racing through dust and rubble while two extraterrestrial beings, gods come to Earth, duke it out above.

Some time later, public opinion has started to turn on Superman—he’s even brought before Congress. (Holly Hunter is terrific as a skeptical Kentucky senator—pity she doesn’t get more scenes.) We see talking heads—real-life media gadflies like Andrew Sullivan and Neil DeGrasse Tyson—weighing the philosophical quandaries of Superman, while the hero himself goes about his solemn duty, rescuing downtrodden folks looking to the heavens for deliverance. It’s not the most nuanced or sophisticated discussion of faith and politics ever committed to film, but in its context, embedded in a loud summer-season-kickoff movie like this, it’s rather striking. It’s engaging on emotional and intellectual wavelengths, and shows Snyder’s expert talents, apparent since his near-perfect Dawn of the Dead, for montage filmmaking. Indeed, the best parts of Batman v Superman play as turgid, bombastic, and really effective music videos for a Hans Zimmer and Junkie XL album about the quaking of the American spirit, and the hard-jawed men who wrestle on its fault lines.

So, there is plenty of good in the film, much more than in Man of Steel. The moral keening of this new film seems largely inspired by the backlash to Man of Steel’s opera of annihilation, as if Snyder is himself grappling with the pervasive criticism that the increasingly massive, city-wide melees so popular among franchise films these days have begun to lose all sense of context. Batman v Superman takes stock of the genuine, human toll of its predecessor, opening the door for the deeper inspection of superhero-ness that gives the film its most gripping, provocative moments.

But before too long, Snyder has shaken off the self-reflection and returned to the senseless clamor of before, bogging down Batman v Superman with an empty seriousness where, for a few inspired scenes, some actual thought has flickered tantalizingly. There is, nominally, a plot: Bruce Wayne (Ben Affleck, angry and withdrawn) doesn’t much like Superman, and Clark Kent (Henry Cavill, alabaster and cool to the touch) isn’t liking what he’s hearing about this vigilante Batman. Meanwhile, Lois Lane is investigating an attack meant to frame Superman as a bad guy (Amy Adams, one of our most talented American movie stars, does her noble best with a role that, at one point, forces her to say “I’m not a lady, I’m a journalist”), Congress is investigating, and a twitchy tech mogul named Lex Luthor is cooking up some sort of plot to shoot Superman out of the sky.