In moviegoing history, there has probably never before been an Event Movie on this scale. “Avengers; Endgame” is the culmination of twenty-plus superhero films, the long-promised summer blockbuster to end all summer blockbusters. And in the capable hands of directors Joe and Anthony Russo, it mostly—if not entirely—lives up to that ambition.

(Mild spoilers ahead)

Following the triumph of mad titan Thanos at the end of last year’s “Infinity War”—the extermination of 50% of all living beings in the cosmos—the surviving Avengers have struggled to accept their new normal. The bulk of “Endgame” picks up five years after Thanos’s victory, as Ant-Man (Paul Rudd) finds his way out of quantum space and meets up with Iron Man (Robert Downey Jr.), Captain America (Chris Evans), Thor (Chris Hemsworth), the Hulk (Mark Ruffalo), and everyone else. As it happens, Ant-Man has a plan for reversing the effects of Thanos’s cataclysm: using special “Pym Particles” to tunnel back through time and seize the six Infinity Stones before Thanos can weaponize them.

(Yes, this is a time-travel movie—just as everyone expected. As such, the number of plot holes is positively ludicrous. But this is also a comic-book movie, so I highly advise not overthinking these.)

Despite its status as a “final” installment, “Endgame” is a fairly restrained affair through its first two acts (on the whole, “Infinity War” probably devoted more of its minutes to bombastic combat). In place of CGI-drenched mayhem, we’re given retrospective glimpses of the Marvel Cinematic Universe (MCU) as our heroes retrace their steps across time to recover the supernatural stones. And happily, that gives the stars of “Endgame”—primarily the original six heroes that starred in 2012’s “The Avengers”—plenty of room to breathe and be themselves.

Now, that’s not to say there’s not a real climax here. The final battle between all of Marvel’s superheroes and Thanos’s monstrous army is one of the most eye-popping spectacles I’ve ever witnessed onscreen—if not the most. And it’s utterly impossible not to sit there with a big, dumb grin on one’s face as Earth’s Mightiest Heroes finally assemble en masse. Frankly, I have no idea how this finale will ever be topped.

(Serious spoilers ahead. Turn back now)

From a narrative standpoint, the greatest success of “Endgame” is its ability to satisfyingly conclude two major character arcs: the stories of Captain America/Steve Rogers and Iron Man/Tony Stark. Tony’s journey—from self-absorbed womanizer to self-sacrificing family man—has been a tale of transformative redemption. Steve’s journey, by contrast, has been one of perseverance: despite being yanked from an age of black-and-white morals into the gray relativism of modernity, he has never once compromised his essential principles. Tony’s tale culminates in his making the ultimate sacrifice; Steve’s ends in a state of virtuous anonymity. To the extent that the whole enormous tapestry of the MCU has really been their story, “Endgame” is a tremendous triumph.

But the same cannot be said of the film’s other characters. The whole first hour of “Endgame” centers on the surviving Avengers sadly reckoning with their changed world: while the Hulk finally finds a measure of inner peace, Thor morphs into an overgrown frat boy more interested in video games than intergalactic heroics. And that’s saying nothing of Jeremy Renner’s Hawkeye, who becomes a murderous avenger leaving a trail of criminal corpses behind him.

None of these arcs—nor those of the film’s more peripheral characters, like Spider-Man or the Guardians of the Galaxy—culminate satisfactorily. This is particularly egregious in Hawkeye’s case: despite amassing the very same “red ink in the ledger” that Scarlett Johansson’s Black Widow bemoaned in 2015’s “Age of Ultron,” Hawkeye reverts to a state of perfect serenity by the movie’s end.

I’d also submit that the deterioration of Thor’s character is one of the MCU’s greatest errors. I’ll always defend the original 2011 “Thor” film because of its surprisingly rich moral subtext: Thor’s final struggle against Loki isn’t an attempt to save his friends, but rather his enemies—the menacing frost giants of Jotunheim, whom Loki plans to exterminate. The much-maligned sequel “The Dark World” didn’t really call that ethos into question. But 2017’s “Ragnarok”—which recast Thor as predominantly a hammer-toting jokester—took an altogether different approach, and the MCU is the poorer for it. At this point, it’s not clear to me that Thor’s character has much room to grow at all. But in fairness, this isn’t entirely the fault of “Endgame.”

(End spoilers)

At the end of the day, “Endgame” is a serious step up from “Infinity War”—in large part because its events feel pretty final. This might not be the end of the MCU, but it is an end, and the film is far better for it (especially given its predecessor’s forced pseudo-cliffhanger). The stories of Iron Man and Captain America, abstracted away from everything else in the MCU, really are as powerful as anything Sam Raimi, Bryan Singer, or any other first-generation superhero film director cooked up.

When I think back over “Endgame,” that’s what I remember—not the stretches of movie that start to drag, not the character arcs that fail to resolve, not the plot holes, but the moments of absolute rightness that bring these heroes’ stories to a close. If this is to be contemporary America’s national myth—that rare thing that can bring divided people together—it’s a good one.