That hero is Carol Danvers, known by multiple names throughout the film. It starts off on the planet Hala, belonging to the Kree people, where the woman who will soon become Captain Marvel is now just Vers, an alien warrior with blue blood, a memory loss problem, and supercharged fists. The Kree are lorded over by the Supreme Intelligence, an A.I. that takes the form the person approaching it most respects. For Vers, that's a person she doesn't recognize, played by Annette Bening. (It's hard not to be wowed in the presence of one of the greatest living actresses.) Vers and her team, including her advisor (Jude Law), are sent on a mission to a nearby planet where the shapeshifting Skrulls have taken one of their own prisoner. Their plans go awry, Vers is captured, and the Skrulls prod her mind, digging through her childhood and more recent history as an Air Force pilot and Guns N' Roses fan for a mysterious clue.
She quickly escapes her captivity using her supercharged fists, and crash lands into a Southern California Blockbuster in 1995. She immediately takes aim at Arnold Schwarzenegger on a True Lies poster in the first of many nods at '90s culture, including needle drops from TLC, Nirvana, No Doubt, and Hole that range in effectiveness. (It was awesome to hear "Celebrity Skin," but Courtney Love's tirade is a weird fit for our noble protagonist.) Vers' arrival attracts the attention of a young S.H.I.E.L.D. agent with two working eyes named Nick Fury (a de-aged Samuel L. Jackson), and the two team together to battle the Skrulls, who are led by the charismatic Talos (Ben Mendelsohn), causing havoc on Earth. To avoid spoilers, I won't say much more, but Mendelsohn's playful performance is a highlight.
The key to all of the action, of course, is Vers' own backstory as Carol. When she was on Earth, she worked with a brilliant scientist, Wendy Lawson (Bening, again), developing light-speed technology for an Air Force-associated organization called Pegasus. Carol spends much of the running time missing a piece of her identity -- even her own name. All she knows of herself at the outset is that she doesn't quite fit in with the Kree, given her penchant for cracking jokes and her tendency to act on intuition rather than steely logic. From the initial moments, it feels inevitable that embracing the former is the key to Carol's ascension to ass-kicking glory.