Full story
Years ago, Carol Danvers destroyed the Supreme Intelligence, the machine that ruled the Kree empire. The planet Hala fell into civil war and, over thirty years, lost its air, its water and its sunlight. To the Kree, Carol is the Annihilator. Now the new Kree leader, Dar-Benn, finds one of two Quantum Bands, a legendary bracelet tied to the network of jump points used for fast travel across space. She uses the Band to tear open a jump point by force, and the damage spreads through the network.
At the same moment, three heroes touch different jump points: Monica Rambeau, on Nick Fury's space station S.A.B.E.R.; Carol, at the new point Dar-Benn opened; and Kamala Khan, in New Jersey, who wears the other Band. The three women's light-based powers become entangled, and every time they use them at once, they swap places. Chaos follows right away: Carol lands in Kamala's bedroom, Kamala lands in space, and the Khan family's house gets wrecked in a fight with Kree soldiers.
Fury brings the three together. Monica, still hurt that Carol never came back to see her after her mother died, is the one who figures out what's happening. Kamala, Captain Marvel's biggest fan, can barely contain herself. The trio heads to Tarnax, a planet where Carol helped Skrull refugees settle. There, Dar-Benn opens another jump point and drains the planet's atmosphere to send it to Hala. The team saves who they can, and the three learn to swap places on purpose. A team is born: the Marvels.
Carol sees the pattern: Dar-Benn is hitting places tied to her, taking resources and avenging Hala. Next is Aladna, a planet where everyone communicates in song and where Carol is married, for diplomatic reasons, to Prince Yan. Dar-Benn steals the planet's water. Then she targets Earth's Sun. On S.A.B.E.R., Carol's cat, Goose, who is a Flerken, has kittens, and Fury uses them to swallow and save the crew. Dar-Benn takes Kamala's Band and tries to use both, but the power destroys her and opens a tear between realities.
Kamala gets the Bands back and, with Carol, powers up Monica so she can close the tear. Monica does it but ends up stuck on the other side. Carol uses her own powers to reignite Hala's sun. Later, Kamala, fired up by the team experience, goes looking for Kate Bishop to start a group of young heroes. In the mid-credits scene, Monica wakes up in a parallel universe where her mother appears as Binary and doesn't recognize her. There she also meets Hank McCoy, the Beast. What happens to Monica is left open.