After being grounded from flying because of what appears to be a brain tumor, Carol Danvers aka Captain Marvel, witnesses a bizarre string of events that mirror pervious battles in her past. With each battle putting her in a situation to where she is forced to use her powers, increasing the brain anomaly. Meanwhile an old enemy has returned, and he has friends; the Broods. Luckily, Captain Marvel has a few tricks up her sleeve as well, The Avengers.
However, once they realize this was all a diversion, the Avengers quickly assemble to find out who wants Carol dead. With the help of Hulk's alter-ego Dr. Bruce Banner, fellow solider Captain America, her best friend Spider-Woman and a host of other allies including S.W.O.R.D., they soon discover that former Kree warlord Yon-Rogg, also known as Magnitron, has been responsible not only for the multiple attacks, but for the brain tumor inside Carol's head.
Knowing that he has been stripped of all Kree power, Yon-Rogg realizes the only thing he has left is revenge against Captain Marvel. He activates horde of powerful Kree sentries and begins his plan to turn Earth into New Hala. Realizing she doesn't have much time left, The Avengers act fast, attempting to stop the rampaging sentries while they search for Yon-Rogg's location. With time running out, Wasp is sent to find the Sersi, who could know where Rogg is.
As the battle for Earth against Yon-Rogg's Kree faction continues, Sersi informs Wasp of Yon-Rogg's location; New York City. There the final battle begins. Cap and Carol make there way to face the former Kree Warlord, who is in the process of materializing New Hala from the sky. There he reveals that the brain tumor in Captain Marvel is in fact, not a tumor at all, but part of him, the source of his power. Carol is devastated to learn this as New York crumbles around her. Knowing they cannot win as long as Yon-Rogg has his power source, Carol makes a noble decision just as her brain begins to collapse, she flys off into space, amidst Spider-Woman's protests, and lets the tumor take her, shutting her brain down.
Immediately, Yon's power fails with his source gone and Captain America takes him down. Meanwhile, the remaining Avengers look up longingly into the sky, knowing full well what Captain Marvel did. Her body floats off in space, eyes shut. They state she is not dead, but that she has changed... she is not the same Carol Danvers. Later you discover that she has lost a majority of her memories, including the names of her friends, even Spider-Woman. She is not the same woman she once was.