Captain Marvel spoilers below!
The Marvel Cinematic Universe is full of mysteries, from the origins of each Infinity Stone to just what the hell the point of that Adam Warlock reveal at the end of Guardians 2 was. Captain Marvel is a prequel to the MCU that serves as an origin story for both the titular character and Samuel L. Jackson's Nick Fury. Now that it's been released, one of the longest-running mysteries in all of the MCU has finally been answered, as fans of the films now know exactly what happened to Fury that cost him his eye and led to him wearing that iconic eyepatch we're all so familiar with.
Set in the 1990s, Captain Marvel actually reveals a lot about Nick Fury's origins and the start of his Avengers initiative. The movie features a de-aged Samuel L. Jackson co-starring alongside Brie Larson's Carol Danvers/Captain Marvel--not to mention a de-aged Clark Gregg as the beloved Agent Coulson--during Fury and Coulson's early days in SHIELD. Besides the uncanny digital effects on these actors' faces, the most notable thing about Fury's appearance in Captain Marvel is that he's lacking that signature, badass, half-pirate-half-super-spy eyepatch. And there's a good reason for that, as Captain Marvel finally reveals the origin of his mysterious eye injury. Captain Marvel spoilers ahead.
To understand what happened to Nick Fury's eye, you first have to understand why everyone's talking about Goose the cat. You see, the cute orange tabby isn't really a cat at all--it's a Flerken, a dangerous alien creature that closely resembles a cat, but is far more powerful. Flerkens possess pocket dimensions in their stomachs, which has the incredible effect of allowing them to swallow just about anything--including, say, Infinity Stones. It also has a mouth full of massive, Lovecraftian horror inspired tentacles that erupt from its eldritch maw and swallow Kree whole, which comes in handy during the film.
Most importantly, the Flerken is a mysterious creature that possesses powers unknown. That becomes important late in the movie when Goose scratches Nick Fury in the eye. Unfortunately for him, it turns out to be no normal cat scratch, ultimately resulting in the eye becoming useless. Guess he should have listened to the numerous other characters who told him not to get so close to the thing.
Anyway, that's it! Nick Fury's famous eye injury didn't come from some epic showdown with murderous aliens or a fight against supervillains from across the wide spectrum of MCU characters. It didn't even come from the car crash early on in Captain Marvel--the bandage Fury sports above his left eye for the rest of the movie turned out to be a red herring. Instead, Fury wears that signature eyepatch thanks to the character's love of cats and a deceptively adorable Flerken named Goose (who also swallows the Tesseract). Who would have guessed?
Of course, Captain Marvel reveals much more about the MCU's past and future than simply what happened to Nick Fury's eye, and there are plenty of Easter eggs. Go check out what the movie's major Skrull changes could mean, the full breakdown on Fury's origin story, and what actually happened in the post-credits scenes. Then, once you've brushed up on all your facts and figures, start working on polishing up your Endgame theories.