It’s been a long time coming, but Marvel has finally released the first teaser trailer for its upcoming superhero team-up to end all superhero team-ups, Avengers Infinity War.

As the clip shows, Infinity War is shaping up to be one of Marvel’s biggest movies ever, uniting the Avengers, the Guardians of the Galaxy, and almost every other superhero Marvel has ever put on-screen in the 17 prior films over the last decade. All these heroes are banding together to face off against Thanos, the big bad that Marvel has been teasing since the post-credits scene of the first Avengers back in 2012.

Marvel first showed off a teaser all the way back in July at parent company Disney’s D23 Expo, and again at San Diego Comic-Con, but for the vast majority of fans who weren’t in the audiences at those events, the trailer marks the first look at the film.

Infinity War is set to be a major, game-changing film for Marvel — so big, in fact, that the story will spill over to a second, still-untitled Avengers movie set for release in 2019.

Along with the trailer, Marvel has also released the first poster for the movie, which doesn’t do much but remind viewers that yes, this is in fact an Avengers movie (although the design is a bit of a stylistic nod to the first teaser posters for the original Avengers and Age of Ultron).

Avengers: Infinity War will be arriving in theaters on May 4th, 2018.