Marvel just threw down the gauntlet. The studio surprisingly debuted the first footage from Avengers: Infinity War, a film that, in Marvel Studios chief Kevin Feige's own words, will "bring almost every single hero" that the studio has introduced since the release of Iron Man 10 years ago. Fans at D23, Disney's fan expo in Anaheim, California, were treated to the never-before-seen footage in a packed Hall D.

Feige was joined by a few friends from the Infinity War cast, including Josh Brolin (Thanos), Paul Bettany (Vision), Elizabeth Olsen (Scarlet Witch), Pom Klementieff (Mantis), Karen Gillan (Nebula), Dave Bautista (Drax), Don Cheadle (War Machine), Sebastian Stan (Bucky), Anthony Mackie (Falcon), Benedict Cumberbatch (Doctor Strange), Tom Holland (Spider-Man), Chadwick Boseman (Black Panther), Mark Ruffalo (Hulk), Chris Hemsworth (Thor), and the man who started it all, Robert Downey Jr. (Iron Man). The cast flew out from the Atlanta set of Infinity War, where production reached the halfway (!) point this week. (For context, Infinity War started production in January.)

It's unclear whether Marvel will release any of the footage online, but MTV News was in the room where it happened, so we've done our best to recap all of the major moments (of which there are many) from the hair-raising sizzle reel.

1. The footage starts with the Guardians of the Galaxy, now with Mantis, fresh off their victory against Star-Lord's dad, Ego. Peter (Chris Pratt) tells the crew to put their "mean" faces on when they come across a great disturbance in the galaxy. Then, and this is a Thor: Ragnarok spoiler, a beaten Thor (Hemsworth) crash-lands on the Guardians's window shield.

2. The Guardians lay Thor on a table, and Mantis awakens him. Thor jumps up and says, "Who the hell are you guys?" Good question, Thor.

3. Thor and the Guardians land on an unknown planet, destruction all around them. Something is terribly wrong.

4. Meanwhile, Scarlet Witch (Olsen) looks distressed as she moves two cars. A female voice says, "Death follows him like a shadow." The scene then cuts to Loki (Tom Hiddleston), who is holding the Tesseract. It looks like he's presenting it to someone. Could that someone be Thanos?

5. The scene again cuts to a school bus in Queens. The hairs on Peter Parker's (Holland) arm begin to stand up, as Peter glances toward the sky. He knows something is up. Spider-Man officially has his Spidey sense!

6. A ship is seen flying toward a planet that's probably Earth. "We have one advantage," Tony Stark (Downey Jr.) says. "He's coming to us." Again, that "he" in question is most likely Thanos.

7. "Fun really isn’t something one considers when balancing the universe," a voice says. Gamora looks on in total horror. It's pretty clear that this voice belongs to her big, bad dad, Thanos. "But this puts a smile on my face." Star-Lord manages to get out an "oh no" before Thanos appears in the flesh through a blackhole — and he's standing! Finally.

8. From there, there's a lot of fighting. Every scene looks like an epic splash page. It's seriously impressive. We get a cool glimpse of Spider-Man's new suit — the one Tony presented Peter at the end of Spider-Man: Homecoming — in action. The black really pops against the red on the suit.

9. There's also an awesome shot of Bucky (Stan) with the Black Panther (Boseman) and the Wakandan army ready to go to battle. Bucky is officially fighting alongside T'Challa in a massive battle scene.

10. Cap (Chris Evans) appears and he looks a little worse for wear. He's also sporting a beard. I repeat, Captain America is sporting a beard. This is not the Cap we once knew.

11. There's a shot of Vision (Bettany) behind bars, and Scarlet Witch looking sad, which doesn't bode well for his chances of survival. Thanos just needs one more Infinity Stone — the one that gives Vision his life force, a.k.a. the one infused into his skull. That would also explain why Thanos is on Earth.

12. Black Widow (Scarlett Johansson) is now blonde, which is cool, I guess.

13. In what is perhaps the most emotional moment of the footage shown, Peter Parker is on the ground, badly injured from battle on what looks like an alien planet. "Tony. I'm sorry," he says through tears. Iron Man has taken off his helmet to hold his hand. WHAT DID THANOS DO TO SPIDER-MAN?! I WILL KICK HIS BUTT.

14. Doctor Strange (Cumberbatch) battles alongside the Guardians and Iron Man on this barren, rocky planet. There's also a brief glimpse of a scene between Doctor Strange, Bruce Banner (Ruffalo), and Stark. All of your Marvel dads in one scene!

15. There's another brutal scene in which Thanos grabs Thor's head and squeezes. It looked just as painful as it sounds.

16. Thanos wears the Infinity Gauntlet, and pulls down part of a moon to battle the Avengers on said alien planet. And then the sizzle ends. He literally pulls down the moon and the title card drops. Now that is how you do a sizzle.

Avengers: Infinity War hits theaters May 4, 2018.