For all of the successes of the Marvel superhero universe, most of the sub-franchises haven’t enjoyed uninterrupted upward curves. Iron Man 2 was a mess, Thor: The Dark World was a bit dull, and Avengers: Age of Ultron seemed tired by comparison with its mega-successful predecessor. Only the Captain America movies have shown consistent progress: starting well with The First Avenger, getting better with The Winter Soldier, and now topping the lot with Civil War.

(All the spoilers below…)

It’s a bit of a turnaround. Historically, Captain America the character has struggled to escape the role of a goody-two-shoes stick-in-the-mud, but Chris Evans has latched onto a core of decent humanity at the heart of the icon. As with the preceding two movies featuring this character, it’s that human core that the story revolves around. Faced with a governmental demand for the Avengers to come under United Nations control, Cap demurs, seeing the need to help wherever necessary as a greater priority.

It’s not an entirely selfless stance: the presence of the Winter Soldier, Cap’s former best friend, as a fugitive from justice is a key driver in how he winds up on the wrong side of the law. In this, Civil War proves far more subtle in its storytelling than the comic book it’s based on—Mark Millar and Steve McNiven’s Civil War was an unsubtle allegory about gun control in which one side was clearly in the right. Here, Tony Stark’s guilt-driven need to control the potential fallout from the superheroic age he kicked off is entirely reasonable, though just as flawed as Cap’s stance.

These three characters—Cap, Winter Soldier, and Iron Man—form the core trio of the movie, but they’re supported by the largest cast yet assembled for a Marvel movie. It’s one of the film’s most impressive achievements that few of those characters come out short-changed. (Though the two-and-a-half-hour running time helps.) The first act can feel a little slow as all the pieces are put into play, but things speed up as Cap goes off the reservation in the second act, leading to a full-on hero-on-hero brawl at an airport (heavily promoted in the trailers, albeit without giving away the most best moments).

Before taking a look at the big denouement, it’s worth noting three of the supporting characters that help make Civil War so much fun. Chadwick Boseman’s Black Panther (set to headline his own movie) proves a wildcard in the conflict between Stark and Cap, following a satisfying storyline of his own with gravitas and conviction. Paul Rudd’s Ant Man offers a very different presence, proving to be a superhero fanboy when he joins Cap’s side, injecting enthusiasm and fun whenever he’s on screen. Lastly, there’s Tom Holland’s Spider-Man, nailing the character in a way we haven’t seen since the second Sam Raimi movie. Holland is perfect as a high school-age Peter Parker, and his stammering surprise at meeting with Tony Stark and wide-eyed wonder at finding himself in the middle of a superpowered battle are the source of much gleeful fun.

With such an embarrassment of character riches, the decision to clear the decks for the finale might seem strange, but it proves entirely the right decision. The three main players in the plot are brought together with Daniel Bruhl’s villain of the piece, who has previously haunted everything that has come before. When the final reveal of his plan comes, it’s of a piece with the rest of the story, kicking off a battle that’s driven by loyalty, guilt and grief and is all the more satisfying for it.

In fact, the fight scenes throughout the film (and there are a lot of them) are uniformly excellent and pleasingly different. Some fantastic stunt work gives a real sense of impact to the action, but just as important is the fact that the script ensures that we always know why people have come into conflict with each other. There are only a few faceless mooks to serve as cannon fodder for the heroes, and the fact that both sides are ostensibly in the right adds a level of tension to proceedings—you’re never entirely sure who should or will win out.

Rather than nitpick any of the slight problems with the movie (there’s only one that jumped out with some thinking later), it’s better to note that Captain America: Civil War shows the benefits of Marvel’s decision to maintain a range of tones across its movie offerings. Unlike DC, which fell in love with the grim-and-gritty nature of Christopher Nolan’s Batman movies, Marvel makes room for both laughs and serious characterisation. All of which pays off here, in its most mature movie to date. There’s action and drama aplenty, but it’s leavened with just the right amount of humour in just the right places.

If this is to be the last Captain America movie (and Marvel seems to have an unofficial strategy of trilogies for its headlining characters), it’s a fine way to sign off on the character’s solo adventures. Black Panther and Spider-Man: Homecoming are much more appealing prospects given what we’ve seen of the characters here, and knowing the Russo brothers are in charge of the Avengers: Infinity War movies is equally exciting. They’ve proved that they can handle a sprawling ensemble cast with aplomb. What they might do with a truly epic crossover will be worth waiting to see.