About a third of the way through Avenger: Endgame’s three-hour running time, I developed a wicked tension headache. And then I realized that it was probably because I’d been blinking back tears, holding a lump in my throat, clenching my jaw and utterly engrossed — not to mention stressed — for the past 60 minutes straight. The thing is, I’m not even remotely what you would call an MCU superfan. So, yeah, the rumors are true: Endgame is a serious emotional rollercoaster. After it was over I heard two male critics comparing how many times they’d each cried. If you do consider yourself an all-in Marvel devotee, prepare thyself!

You already know why the stakes are so high for this film. Not only have 21 other Marvel movies been leading us to this moment, but also half of the superheroes those movies revolved around were wiped out by Thanos (Josh Brolin) at the end of last year’s Avengers: Infinity War. Thanos succeeded in his mission to acquire all of the Infinity Stones, pop them in his gauntlet, and kill half of the Earth’s population with a snap of his fingers.

However, several Avengers and their allies survived the snap. And they are each in different stages of grief, denial and acceptance when we first see them again. Cliff Barton/Hawkeye (Jeremy Renner) has been hanging out with his family on a farm. Bruce Banner/The Hulk (Mark Ruffalo) has finally embraced his dual identity. Tony Stark/Iron Man (Robert Downey Jr.) is trying to find a state of peaceful acceptance. Steve Rogers/Captain American (Chris Evans) is still helping people, albeit on a much smaller scale. Natasha Romanoff/Black Widow (Scarlett Johansson) has continued policing the planet. Thor (Chris Hemsworth) has … taken a different approach.

But Scott Lang /Ant-Man (Paul Rudd) missed all of the drama. He’d been stuck in the quantum realm since the end of Ant-Man and the Wasp. I don’t think it’s a spoiler to say that he does indeed come back (the circumstances of how he comes back, which I will not reveal, are hilarious) and is thrown for a loop when it fully sinks in to him exactly how much he’s missed. But his time in the quantum realm is also the inspiration for a far-fetched scheme he brings to the surviving group. His idea plants the tiniest seed of hope that perhaps there is some way, some small chance, that they could still save everyone who was lost.

I was expecting certain things to happen in Endgame. After all, with every other superhero movie — except the end of Infinity War — I’ve easily predicted the arc of action and how things will wrap up. I’m sure you have, too … it’s usually quite obvious. However, Endgame surprised me. Certain things happened that I expected, yes. But they happened early on, and then the twists started coming. So while the film was truly heart-wrenching in parts, laugh-out-loud funny in others and headache-inducing intense throughout, I think the main reason I enjoyed it so much is that I could not have foreseen how everything ended up unfolding for these beloved characters.

As a writer, I can’t help but respect the master feat that returning directors Anthony and Joe Russo, along with returning screenwriters Christopher Markus and Stephen McFeely, have pulled off here. They somehow juggled literally dozens of characters in this film, yet no scene ever felt like an obligatory “Oh crap, we still gotta get this guy in somehow” moment. Audiences are treated to meaningful character development and long-brewing issues being resolved in the run-up to the inevitable action-packed showdown (always the least interesting part of these movies to me).

With a cast this large, it’s inevitable that some characters will have more to do than others — but it’s not necessarily the ones you’d expect. For example, Nebula (Karen Gillan) is a key player this time around. Downey as Stark/Iron Man gives a downright Oscar-worthy performance. Absolutely riveting and unforgettable. Rudd was a standout for me as well, not for his usual one-liners (which are great) so much as for a few brief dramatic scenes where his facial expressions are burned into my memory. Renner, Evans and Johansson also bring their A-game, and Hemsworth fully embraces and flexes his comedic chops. (Unfortunately he can’t really flex his physical muscles anymore. You’ll see why.)

Those who have seen all of the previous Marvel films will be the most rewarded. Actually, I take that back. Those who have obsessed over all of the previous Marvel films and could recite them forward and backward will be the most rewarded, as past plot points are heavily revisited, and Easter eggs and allusions abound. But unless you know absolutely nothing about these characters or their respective franchises going into this film, the payoff is huge. And then you’ll probably want to see it again.

One tip: there’s no end credits scene this time. Making Endgame feel that much more special … and ensuring the realization hits home for fans that a truly epic chapter has finally closed for good.