As any Marvel movie fan knows all too well, you can't leave your seat until after the credits are finished rolling — a new Marvel movie means a new post-credits scene or two (or more) to further expand the cinematic universe. Thor: Ragnarok has two post-credits scenes: one that sets up the future for the main characters and one that's just a little bit of silly fun. Let's break down what that Thor: Ragnarok post-credits scene means and how it might tie into future Marvel movies.
Spoiler alert: If you haven't seen Thor: Ragnarok yet, don't read on. Basically, the big post-credits scene serves to set up the next Avengers team-up movie, Infinity War. After Thor and Loki's home world of Asgard is destroyed by Ragnarok, they and their band of Asgardian survivors set off on a spaceship to Earth. But something blocks their path: a gigantic spaceship. That's all we see in the brief scene, but it is very likely a huge clue about how Thor and Loki's story will begin in Avengers: Infinity War.
Some viewers might think the ominous ship could be piloted by fellow Marvel heroes the Guardians of the Galaxy, but it seems more likely that the ship is connected the the next major villain Thanos. The ship looks much more like the Chitauri ships we first saw in The Avengers, and nothing like the ship we last saw the Guardians riding in at the end of Guardians of the Galaxy Vol. 2. The Chitauri are servants to the alien warlord Thanos, who we've seen from previous post-credits scenes will be the main antagonist of the Avengers in next year's Avengers: Infinity War. So basically, the post-credits scene is foreshadowing Thor and Loki being captured by Thanos at the beginning or in events immediately prior to Infinity War.
So why is Thanos targeting the Asgardians? As with almost everything in this universe, it's probably all Loki's fault. The main thrust of Infinity War will focus on Thanos attempting to collect the six Infinity Stones, which are cosmic artifacts the hold immense power. And at the end of Thor: Ragnarok, Loki actually has one of the Infinity Stones in his possession, which explains why Thanos is after him.
Before Asgard was destroyed, we saw Loki eyeing the Tesseract in Odin's Vault. The Tesseract is the small blue box Loki wielded in The Avengers that allowed him to rip dimensional holes into space to jump between planets. But it is also one of the six Infinity Stones, specifically the Space Stone. Loki was actually sent to Earth by Thanos and the Chitauri at the beginning of The Avengers to retrieve the Space Stone for them, and they even gifted him with the Mind Stone (embedded in a staff) and the Chitauri armies to aid in his quest. But of course, Loki was defeated and Thor locked the Tesseract up on Asgard, where it has stayed untouched until Loki seemingly decides to grab it at the end of Thor: Ragnarok.
Obviously, Thanos is probably not too happy with Loki. Not only did the mischief god fail at his task of bringing the Space Stone to Thanos, but he also lost the Mind Stone in the process. In Avengers: Age of Ultron, the Mind Stone actually takes a sentient, humanoid form and allies with the Avengers as Vision. The post-credits scene of Thanos' ship looming over Thor and Loki could definitely be foreshadowing Thanos taking the Space Stone from Loki at the beginning of Infinity War to start his collection of the Infinity Stones.
Avengers: Infinity War is set to be released on May 4, 2018.