Most big action movies are built on the structure of nineteenth century melodrama: a protagonist hero, trying to accomplish something laudable, while also winning the girl. Marvel superhero movies are no exception. Each of the many many Marvel superheroes have starred in movies of their own, and each followed that tried and true formula. Infinity War is the exception. It’s a quest movie, in which the protagonist works through barrier after barrier, towards a goal, opposed by a variety of obstacles and antagonists. Only, in this case, the protagonist is also the film’s villain. He drives the action; his choices and the objectives of his quest are what structure the movie.

Thanos (Josh Brolin) is the movie’s protagonist/villain. He spends the movie trying to gather six Infinity stones, for which he has acquired a special glove. Combined, the stones will give him awesome powers. It frankly reminded me of the last couple of Harry Potter movies, in which Harry and Hermione and Ron are trying to find and destroy horcruxes. Same basic dynamic–where are they, who has them, how can we get hold of them. And Thanos has an overarching purpose, and, seen through one lens, a noble one. He wants to end poverty and hunger. He wants to improve life on every planet in the universe. He thinks the biggest problem in the universe is overpopulation. So his plan is to kill half the sentient beings everywhere. Kill 50% of everyone. Wipe them out. An instant, appalling cure for scarcity of resources. Yikes.

So, though he rather looks like an overgrown, overly-muscled oaf, he’s actually more interesting than that. His cruelty and violence have a design and purpose. He is capable of compassion and feeling; in fact, he believes himself to be acting out of genuine empathy. He honors a valiant opponent. He loves his daughter, Gamora (Zoe Saldana), and forgives her (as he sees it), betrayal. He clumps across the screen with an inexorable power and authority. And the various permutations of Avengers who work improbably together to defeat each of his attempts to grab a stone seem, at times, like annoyances, rather than as serious threats.

Of course, he’s also a brutal mass murderer. He is absolutely the villain of the movie. I just found it interesting to see how, I don’t know, defensible his plans were. Reprehensible, to be sure. And in need of being defeated, absolutely. Our sympathies are with the various superheros trying to stop him. Most of the time. But he drives the plot, and one of the immutable rules of dramatic structure is this: you will always root for the protagonist. And we do, sort of. Kind of. At least a little bit.

We’re also rooting for the main Avengers, of course, especially for Thor (Chris Hemsworth), who is battered and ravaged and intrepid throughout, for Iron Man (Robert Downey Jr.), especially through his relationship with teen protege, Spiderman (Tom Holland), and Dr. Strange (Benedict Cumberbatch), whose gifts include an insight into how Thanos can be defeated that I would really have appreciated the durn movie sharing with us out there in the cheap seats. Also, strangely prominent, Vision (Paul Bettany), who has one of the stones embedded in his head, and is quite willing to sacrifice himself for the greater good.

In fact, that leads me to another theme of the movie. Let’s suppose, hypothetically, that you were told that you could stop Hitler, prevent the Holocaust. But to do it, you had to kill the one nearest-and-dearest person in your life. A spouse, a parent, a child. Someone you loved deeply; someone you’ve built your life around. Well, would you do it? Would you kill someone you cared about in order to prevent the mass slaughter of millions (or even billions) of strangers? I’ll tell you right now, I’m not sure I would. Logically, it’s an easy call: weigh one life against billions? Emotionally, I don’t know what I’d do. What a dreadful, wrenching dilemma.

Well, that particular moral dilemma is reinacted repeatedly in this movie. Several characters are faced with it. They don’t respond uniformly. They make different choices. It was a fascinating conundrum to build a superhero movie around. (Especially if we believe that superheros are somehow unique, more than ordinary humans, and therefore especially to be valued). It gave the movie a bit more heft than we’re used to with most superhero movies. It raised the stakes.

Of course, there are many many characters in this movie, and a lot of them aren’t really given much to do. Among other things, it includes three of the four Chrises (Evans, Hemsworth, Pratt), so we can do a side-by-side acting-chops comparison. (Hemsworth wins, and it’s not close: Captain America (Chris Evans), isn’t given much to do, and Starlord (Chris Pratt), is just sort of goofy through much of the movie. (Yes, this is an Avengers movie in which Vision is much more prominent than Captain America). Black Widow (Scarlett Johansson), is just sort of there, while Scarlet Witch (Elizabeth Olsen), gets a lot more screen time and more satisfying acting challenges. It’s very clear to me that Black Panther‘s success took Marvel by surprise, or T’Challa (Chadwick Boseman) would have been more central to the plot than he was. Meanwhile, the Hulk (Mark Ruffalo), spends a lot of the movie trying to emerge–Bruce Banner doesn’t seem to have gained much control over his ferocious alter ego. Two final actor mentions. Karen Gillan, so great in the last Jumanji movie, reprises Gamora’s sister, Nebula, and was terrific in that tiny role. And Peter Dinklage is in it, playing a dwarf, only a really tall one. Kudos.

Considering how high the stakes are throughout, the movie had a surprising amount of comedy, which made it’s nearly three hours running time go down a little more easily. (I was never bored, though, I’ll say that for it). I don’t want to give away any spoilers, but I was rather comforted by the thought that superhero deaths are often fairly temporary. Whew.

Overall, though, I found it impressive, a bit overwhelming, and, considering it had fifty seven main characters, surprisingly compact. I mean, if you haven’t seen it yet, you’re going to. That’s essentially mandatory, right? But I expect you’ll enjoy it, sort of, as I did, pretty much. Kind of. Stay past the credits. There’s a post-credits sequence which I found completely baffling, but which probably represents a ray of hope, or something. And at least we get to see Samuel L. Jackson say half of his favorite word. So there’s that.