When Thanos first appeared in the post-credits scene for The Avengers, fans speculated as to how he would fit into the Marvel Cinematic Universe. The character makes for a mighty match against the Avengers given his power, but his motivations have been downright weird throughout the comics. With Avengers: Infinity War on the horizon, in which the Avengers will finally face off against the Mad Titan (played by Josh Brolin via performance-capture), it’s finally time to see what this dude is all about.

In the most well-known Thanos comics arc, the character is actually driven by love. He’s infatuated with Death, an actual character, and in order to prove his undying devotion to her he sets out to destroy the Avengers and humanity once and for all. There was speculation that perhaps Cate Blanchett’s character Hela from Thor: Ragnarok, the self-described Goddess of Death, might be filling this role, but Marvel Studios president Kevin Feige is now ready to start teasing a bit of what motivates Thanos, and it’s quite a bit more complicated.

Speaking with EW, Feige says Thanos is actually driven by his tortured past:

“He’s from a planet called Titan that’s no longer inhabited because of things that he thought he could help prevent, and he was not allowed to do that. What he feared most happened, and the planet and everybody on it basically went extinct. He vowed not to let that happen again. He thinks he sees the universe going down the tubes. He thinks he sees life expanding outward unchecked. That will bring ruin, he believes, to the universe and to that life.”

Thanos thinks that if he kills half of all life in the universe, he’ll restore balance. To do so, he needs all six Infinity Stones to power his Infinity Gauntlet, which in turn will give him the ability to bend time, space, energy, and the laws of physics and reality. Basically if Thanos gets all six Infinity Stones, he’ll be unstoppable.

That’s where the driving plot of Infinity War comes in, which co-director Joe Russo describes as a heist movie of sorts:

“He’s on a hunt. We’re using a bit of a ’90s heist genre component. Thanos is on a smash-and-grab, and everybody’s trying to catch up the whole movie.”

So it sounds like Thanos will be spending most of Infinity War hunting (and likely getting) the Infinity Stones, while the Avengers are playing catch-up, trying to stop him. Paul Bettany’s Vision no doubt plays a major role in this, as the Mind Stone is embedded in his forehead and is what gives him his power. We saw in the first trailer that Thanos tries to pry this stone from Vision’s head, so yeah, things don’t look great.

This also kind of explains why this story is divided into two movies. Infinity War is the arrival of Thanos and his hunt for the Infinity Stones, while the untitled Avengers 4 will likely find Thanos in possession of most if not all of the Stones while the Avengers make one last stand. It’s always possible that the whole Death thing does come into play, and I’d be surprised if Feige was revealing Thanos’ entire motivation here, but it’s certainly an intriguing storyline for the Mad Titan.