Captain America: Civil War shouldn’t work. Avengers: Age of Ultron tried a year ago to tell a more complicated story than The Avengers, and even though there were aspects of that film that improved on The Avengers, Ultron showed obvious straining points. With Captain America: Civil War bringing back many of the original Avengers, the new Avengers, a few characters from Captain America: The Winter Soldier plus a handful of new players, the sheer number of characters alone should sink this film. At the very least, it should seem like Avengers 3, not a Captain America film.

But no. Captain America: Civil War is a stupendous achievement for Marvel Studios. It’s an intelligent film that plays to the key strengths of the best of the MCU films: keeping the focus on characters first, spectacle later. It pits superhero against superhero, and in spite of featuring one character in its title, isn’t above showing how both sides are right – and wrong. More importantly, the film works as a proper Captain America film while also giving each character an appropriate amount of presence – a tricky feat when you’re talking about a dozen or so superheroes alone.

When a mission in Lagos goes awry, it’s viewed as the final straw for the destructive fallout that’s marked multiple Avengers battles. The response from the global community is a document called the Sokovia Accords, which would place the Avengers under the supervision of a UN council. The Accords are met with approval by some heroes, most prominently Iron Man (Robert Downey Jr.), who believes that the loss of innocent lives has become too large. With a body supervising the Avengers, the team can be kept in check and people all over the world can be safer. Others, though, aren’t so sure. This side is led by Captain America (Chris Evans), who feels that the Avengers are still the best judges of when, where and how to use their powers.

The tensions between the two sides are tested when a terrorist attack is connected to the Winter Soldier (Sebastian Stan), and Captain America feels compelled to try and save his old friend. The Sokovia Accords are put to the test as Captain America tries to protect his friend and Iron Man is urged to bring him in, all while the mysterious Helmut Zemo (Daniel Brühl) operates in the shadows.

While not every single MCU film is directly relevant to this film, Captain America: Civil War requires viewing at least the previous Captain America, Iron Man and Avengers films to see these characters develop. With Captain America and Iron Man leading the two sides, each character’s rationale for supporting their side makes sense in the broader context of the universe. Iron Man may have done a lot of good for the world, but there’s no denying how responsible he is for many of the bigger incidents that have plagued Earth since his arrival – most notably Ultron’s creation, but also in promoting war so much in his time pre-Iron Man that he provided motivation for Scarlet Witch’s (Elizabeth Olsen) creation. He’s aware how even with the best intentions, the Avengers can destroy lives. We’ve seen it time and time again.

But Captain America’s position also has plenty of reasoning. From Hydra to S.H.I.E.L.D., he’s seen how large organizations can be destructive forces, and how they can obfuscate evil intentions behind layers of bureaucracy. Is it any wonder he wouldn’t trust another bureaucratic organization overseeing the team, especially when they’re likely to have their own agendas?

There’s a reason this is the 13th film in the MCU, and not simply the third film in a trilogy. We’ve seen many of these characters over multiple films. We know how they operate. We know their motivations. We know how they’ve evolved over the years. Captain America: Civil War does work as a natural end to the trilogy of Captain America movies, in that it concludes a definite arc about Steve Rogers finding his place on Earth. But it’s so much more than that. It’s quite possibly the best use of Iron Man since, well, Iron Man, but with the added weight of everything that’s come in his four major appearances since that film. Black Widow (Scarlett Johansson) is, appropriately, a voice of reasoning somewhere in the middle of the two sides, even though she has her own reasons for choosing one side. And everyone involved has their own reasoning for getting involved, and in nearly every case, it makes complete sense (note: Hawkeye is the exception, because of course he is).

This includes the film’s two major new characters. The more prominent character, of course, is Spider-Man (Tom Holland), making his MCU debut. From his relatively brief appearance in the film, it’s easy to see how they could write him out. He’s not important to the film. But his presence is fun. No offense to Tobey Maguire or Andrew Garfield, but Tom Holland’s Spider-Man is, with his brief appearance here, the definitive take on both Spider-Man and Peter Parker. He’s young and clearly inexperienced. He’s a bit of a fanboy. He’s delightfully quippy, and when he gets into the action, he adds something new.

But the bigger addition is Black Panther (Chadwick Bozeman). T’Challa, the prince of Wakanda, is a driving force throughout the film, particularly once he suits up as Black Panther to hunt down the Winter Soldier. He has his own reasons for supporting Iron Man, but he has a clear arc of growth as he encounters the others fighting. With him, the proper introduction of Wakanda also promises something new and different for the MCU going forward.

There’s also the matter of Zemo, the film’s nominal villain. He takes a backseat to the fighting between the heroes, but unlike how most MCU villains are woefully underutilized, Zemo’s presence is eerily, chillingly perfect. When Zemo’s plan is finally revealed, it’s shocking – and when his own motivations are also revealed, they make sense. He’s looking for something other than world domination, or the destruction of mankind. He’s not following the formula for what we’ve seen in most of the MCU’s villain slots, thankfully.

Of course, well-developed characters and a great story are great, but the film’s biggest hook is seeing Captain America, Iron Man, and the rest fight each other. And my god, it’s handled perfectly. Joe and Anthony Russo already impressed audiences with their action sequences in The Winter Soldier, especially in how they managed to make Captain America’s fighting style hit hard, but that looks like nothing compared to what they do in Civil War. There’s a fluidity to the action that makes it easy to watch, even when a dozen superheroes are duking it out. Everyone’s powers are highlighted well, in spite of the many differences between the characters’ abilities.

Captain America: Civil War is a stunning addition to the Marvel Cinematic Universe. It’s filled with the elements that have drawn audiences in over the years, from humor to heart. It’s also not afraid to get rough with its characters, who may take positions in the film that surprise some of their fans. It’s morally complex, and it’s not afraid to leave on a note that’s something other than upbeat. It’s a promising start to what may shape up to be a very different MCU phase, and once again raises the bar for what to expect from this particular franchise.

Captain America: Civil War • Rating: PG-13 (for extended sequences of violence, action and mayhem) • Runtime: 146 minutes • Genre: Action • Cast: Chris Evans, Robert Downey Jr., Scarlett Johansson, Sebastian Stan, Anthony Mackie, Don Cheadle, Jeremy Renner, Chadwick Bozeman, Paul Bettany, Elizabeth Olsen, Paul Rudd, Emily VanCamp, Tom Holland, William Hurt, Daniel Brühl • Directors: Joe Russo, Anthony Russo • Writers: Christopher Markus, Stephen McFeely • Distributor: Marvel