Seventeen movies (18 if you count next year’s Black Panther) has all led to this: Thanos taking possession of the Infinity Gauntlet in an attempt to rule the universe. Disney and Marvel dropped the first trailer for Avengers: Infinity War on Wednesday, and it’s the farthest thing from Thor: Ragnarok’s happy-go-lucky tone.

Note that there are potential spoilers ahead

We open with a look at an alien planet shrouded in a beautiful orange hue. Tony Stark (Robert Downey Jr.), possibly on the planet, looks to be in bad shape as he quietly contemplates the situation. A voiceover helps explains why the Avengers were formed in the first place.

As the voiceover continues, a confused (and shirtless) Bruce Banner (Mark Ruffalo) lies in a hole in what looks like the Sanctum Santorum. We know this because the next shot we see Doctor Strange (Benedict Cumberbatch) and Wong (Benedict Wong) standing over Banner in bemusement.

Banner has clearly fallen from a great height, but we don’t really know the context of the situation. What’s notable is that this is the first time Banner has been on Earth in over two years—not since the end of Avengers: Age of Ultron has he been home.

The next shot we see Scarlet Witch (Elizabeth Olsen) comforting Vision (Paul Bettany), who is no longer in android form. Rather, he looks like regular Paul Bettany; the only difference is the Mind Stone is clearly still implanted in his head. But it might not be there for long…

Thor stares out at space from, followed by a look at a more settled Banner, who appears to be in Wakanda working on Hulkbuster armor. There are reports that claim it won’t be Iron Man who controls the armor in Infinity War, but Banner. That could be why he’s working to salvage and improve upon the armor, which was used in Age of Ultron.

The fact that Black Widow (Scarlet Johansson) is there is worth mentioning because the two had a close relationship before Banner decided to get out of Dodge at the end of Age of Ultron. At this point, it’s unclear if their relationship will go back to the way it was, but given what Banner has been through, that’s highly unlikely.

After 30 seconds of mostly exposition, we start to get some tidbits about Infinity War’s plot. We revisit Doctor Strange’s Santorum, which is now occupied by Tony Stark. A voiceover from Thanos (Josh Brolin) threatens the Avengers with defeat. “In time you will know what it’s like to lose,” Thanos says.

As Tony Stark goes to investigate some sort of commotion outside, we cut to Spider-Man (Tom Holland) sitting on a school bus when the hair on his arm perks up, indicating his Spidey senses are tingling. He looks back toward New York City and sees some kind of giant ring structure hovering over the city. No doubt a portal for Thanos to travel through.

Among rubble, Tony Stark takes off his sunglasses and looks toward the structure, obviously concerned by what he’s seeing. As several people have pointed out, it looks like Tony has reinstalled his arc reactor, which he removed at the end of Iron Man 3. We then see Loki, presumably handing Thanos the Tesseract (Space stone) in a big sign of allegiance.

After seeing the danger from afar, Spider-Man springs into action wearing the spiffy new armor presented to him at the end of Spider-Man: Homecoming. It’s unclear what Spider-Man is hoping to achieve, but he’s managed to make his way atop the ringed structure.

It’s tough to tell where the next shot is taking place, but it looks like it’s out in space. Thor stands in the middle of a ringed structure as he attempts to activate switches.

The next shot is our first good look at the Black Order’s Proxima Midnight, who angrily throws her spear at a mysterious cloaked figure. The cloaked figure’s secret identity is revealed to be Steve Rogers (Chris Evans), who has grown a pretty manly beard since the last time we saw him.

A reassembled Hulk Buster armor trounces across a field in Wakanda. It’s pretty obvious Wakanda is going to be a major fixture in Infinity War, otherwise we wouldn’t keep visiting the location. This leads us to believe the secretive country is home to the Soul Stone, which could explain how Wakanda has developed such advanced technology.

And it could be why the country is being invaded, which we see unfold in the next few cuts. I have no clue what the four-armed alien is, but he doesn’t look friendly. We later see that the alien invasion sparks an all out war.

Moving away from Wakanda, we see Thanos slam Spider-Man onto the ground. It’s tough to tell where this fight is taking place, but it could be that alien planet we see in the beginning of the trailer.

Vision is back in his android form and it sure looks like the Mind Stone is being pried from his head. It’s unclear who he’s being attacked by, but it’s probably someone in the Black Order. The weapon being used looks a lot like the scepter Loki used to have.

We come back to Thanos wielding the gauntlet (now outfitted with the Space Stone and Power Stone) as he hits Iron Man with a haymaker. The Space and Power stones were thought to be safely protected, so it’ll be interesting to see how Thanos comes into possession of them.

A war unfolds as Falcon (Anthony Mackie) soars across the battlefield duel-wielding automatic weapons. Then Captain America leads an attack with some of his crew following close behind, including Black Panther (Chadwick Boseman), Hulk, and Winter Soldier (Sebastian Stan). Cap is wearing some kind of wrist guards that look like they’d fit well on Black Panther’s suit. Also of note is War Machine (Don Cheadle) looks to be back in business following his injury in Captain America: Civil War.

Once the Infinity War logo is displayed, we get one final shot that bridges the gap between the Avengers and the Guardians of the Galaxy (complete with adolescent Groot).

While the trailer shows us a lot, and even gives us some information about the plot, it still leaves out a lot of key information. Which is a good thing! Thanos looks like he might be the Marvel Cinematic Universe’s first real villain, and a great way to help usher in the end of an era for many of these characters.

We find out what happens when Avengers: Infinity War hits theaters on May 4, 2018.