One way or another, this was always going to be something of a watermark movie for Marvel. At this stage - a hefty 19 films in - it was the first occasion that the Marvel Comics Universe came together, and fans have been hoping that this cinematic equivalent of a comic book crossover would work.
They will not be disappointed. This is, ultimately, a jaw-dropping game-changer.
And there's even plenty for those feeling a little bit (or even a lot) jaded with the seemingly endless supply of superhero movies. Without giving too much away, Avengers: Infinity War basically takes The Empire Strikes Back model and chucks it out the window. This is pretty much as dark as Marvel gets.
The plot is straightforward: a nasty piece of work called Thanos, who's been on the fringes of several previous Marvel films, finally takes centre-stage. A heavily CGI-ed Josh Brolin plays the part, and right from the off you know this one's a really bad egg.
Thanos wants to collect all six Infinity Stones, which collectively hold unimaginable power, and use them to treat the universe as his plaything. Only one thing can stop him, and that's everyone who's ever fought the good Marvel fight.
As his presence is felt on Earth and elsewhere, and his collection of Infinity Stones increases, various Avengers, ex-Avengers, Guardians of the Galaxy, Black Panther folk - anyone with special powers or an interesting look, basically - gather together to take on Thanos.
What follows is a mix of epic battles, some great one-liners and smart remarks, superb CGI and a rollercoaster ride previously unmatched on celluloid by either Marvel or DC.
You won't get any spoilers from me, but what you will get is a recommendation to go see this film and have a ball - and a plea to not reveal what happens to anyone who hasn't seen it yet.
Or else I'll send Thanos around.