Avengers: Infinity War has quite a few significant achievements. Special effects, for example. But the two most salient ones are Josh Brolin’s performance (of a CG character, no less) and the pacing. Directors Russo and screenwriters Christopher Markus and Stephen McFeely do an extraordinary job juggling the large cast and various storylines, which start splintered, then come together. But it’s the tension is the thing. The film opens with the introduction of a countdown clock, with the literal fate of the universe in the balance–the introduction’s both to the audience and the majority of the characters–and with that threat, the countdown is always present. There’s always more tension they can ratchet as things get more and more dire. It culminates in big finale, of course, with lots of moving pieces needing to sync up for that finale to work. But the most impressive thing is when, at around an hour and fifty minutes into the film (which runs two and a half hours, albeit with a questionable ten minute end credit sequence before the Marvel movie post-credits teaser), it becomes obvious they aren’t going to have time to wrap it up. The film’s so good at maintaining intensity, so good at latching on to the characters’ determined hopefulness, when defeat becomes visible and probable… it’s a shock. Even though there can’t be much other outcome, given the movie can’t really go on forever, can it?

Even if one of the big finale twists is a bit of a cheat since it relies entirely on something the audience (not to mention the characters) have any idea is possible.

Of course, what’s possible is what’s in question in Infinity War. Giant blue space alien (Brolin) is searching for six “infinity” stones, which–explained in a first act lecture to the audience (and Robert Downey Jr.)–will allow him to remake reality. Brolin starts the movie fighting with Chris Hemsworth out in space, but then goes off on his own storyline–arguably the film’s most successful, though it’s got limited competition and is the only consistent arc (thanks to Brolin’s shockingly good performance). How Brolin’s not just able to bring depth to the CG giant–which has far better CG than when Mark Ruffalo hulks out–also in terms of how he never gets caught up in the gooniness of the whole thing. Directors Russo play the whole thing straight–one of their greatest touches is treating Infinity War like an impromptu trip through the galaxy–but it wouldn’t work without Brolin. Everyone else who has to deal with the gooniness? Well, either it gets worked through like with Downey, Tom Holland, and Benedict Cumberbatch or utterly avoided like with Chris Evans and Scarlett Johansson. Hemsworth is somewhere in the middle. He spends most of the movie with Bradley Cooper’s CG wiseass mercenary raccoon and straightfaces it through the gooniness. Everyone else in his scenes is CG (they also bring along the talking tree “voiced”–or audio filtered–by Vin Diesel).

Anyway. With Brolin, there’s gravitas in the fantastical alien stuff. With Downey’s plot line or Evans’s, there’s not. Even with Downey on a space ship hurtling through hyperspace (presumably, otherwise the Marvel universe is real small), no one wants to get too bogged down with the logic. Hemsworth, hanging out with Cooper and the rest of the Guardians of the Galaxy crew, acknowledges the existence of the fantastical without wanting to deal with it. It’s a wise move from the filmmakers. The Russo Brothers get better performances out of Galaxy regulars Chris Pratt and (especially) Zoe Saldana than their feature movies ever suggested possible. Though Pratt’s still way out of his depth opposite Downey, which is made even more clear when Holland and Cumberbatch are able to keep pass. With Holland even surpassing Downey, in no small part thanks to Downey’s acquiescence. They have a wonderful rapport.

The storylines follow the ostensible Avengers “big four”–Downey, Hemsworth, Evans, and Ruffalo. Though Ruffalo is just moving through where he’s playing second fiddle. First it’s to Hemsworth, then to Downey, then to Evans. Ruffalo’s fine and likable as ever, but… Infinity War goes far in showing, while Ed Norton might be regretting the profit sharing, he didn’t miss out on any great acting opportunities with the franchise.

Evans also ends up supporting other storylines, like Paul Bettany and Elizabeth Olsen trying to figure out how they’re going to survive the movie. Bettany is an android superhero (though he’s a distressingly weak android superhero in Infinity War) who has one of the rocks Brolin wants in his head. Olsen’s the woman who loves him; she’s also a superhero and the only one who can destroy said stone to save the universe, if need be. Evans protects them? He brings along sidekicks–Johansson, Anthony Mackie, Don Cheadle, and eventually Sebastian Stan–to help, but even they get a little more to do. Johansson bonds with Danai Gurira (after Evans and company become second–or third–fiddle to the Black Panther cast), Mackie and Cheadle have some rapport. I guess Stan doesn’t really get anything. But then neither does Chadwick Boseman, who’s the actual Black Panther. He’s scenery.

And then they get Ruffalo lumped in too because… the movie doesn’t actually need him. It’s kind of shocking how good the CG works with Brolin’s character versus Ruffalo’s Hulk. I know I mentioned it already, but it’s really striking.

Anyway. Hemsworth teams up with Pratt, Saldana, and the other Guardians team members who get almost nothing to do in the film–especially not after their first scene confronting Brolin; an Infinity War needs cannon fodder, after all. He’s got his quest with the CG Guardians and some fun moments with Cooper; Peter Dinklage shows up at some point in there too.

Then there’s Downey, who’s got Holland and Cumberbatch with him as they hurtle through the galaxy for a showdown with Brolin. They think. They eventually team up with the Guardians cast, leading to those scenes where we have to pretend Pratt can hold his own opposite Downey. Oh, right. It’s after Pratt can’t hold his own opposite Hemsworth and every single character in the movie makes fun of him for it. Good scene, but whatever.

So a lot going on. Because then there’s also Brolin’s whole arc, which involves adoptive daughter Saldana (he took her in after killing her mother and half the population of her planet). Lots going on, all at once. When the movie gets to the third act and all the storylines are going fullsteam–Brolin can instantly teleport between them, which helps to streamline–it’s truly astounding what editors Jeffrey Ford and Matthew Schmidt manage with their cutting. The film has a rhythm to it already, but they’re able to rev it something spectacular for the finish. Infinity War is a technical marvel. No pun.

Alan Silvestri’s score even recovers from the first act, when it’s focusing on repeating franchise themes.

Performance wise… Brolin’s best. Then Downey. They get the most to do. Their showdown, for instance, hints at some great nemesis possibility. The movie’s just too big (and already too long when they get together) for it. Then Holland? Holland doesn’t get a lot to do after the first act, especially not once Pratt and company join his storyline, but he’s always great support for Downey and he’s got the film’s best single scene (for a non-CG actor, anyway). Then Hemsworth. Because after Hemsworth everyone is fine, but not particularly standout. Though Saldana, Bettany, and Olsen all have some rather good moments; Saldana because it’s opposite Brolin’s CG giant alien, Bettany and Olsen because they’re able to ooze chemistry even though Bettany’s caked in red body paint.

Evans, Boseman, Cumberbatch, whoever. They get their jobs done. The movie doesn’t task them with a lot and always implies if they got another scene or two, they’d be quite good. The rapport between Johansson and Gurira, Cheadle and Mackie, whoever. The film implies potential, but keeps it in check because the trains have to run on time.

Even Pratt’s fine. Karen Gillan’s still not good. And the movie doesn’t do poor Pom Klementieff any favors.

Just getting to the finish line with Infinity War is a win for directors Russo and the screenwriters. Getting it to the finish line with so much good stuff along the way… the film’s a lot more successful than should even be possible, given it’s so seeped in franchise continuity and bloated with characters. The filmmakers nimbly hop through it all. Because, frankly, they get to leverage it all with Brolin’s singular, phenomenal performance.