The full story
Carol Danvers has been alone in space for years, investigating a strange phenomenon affecting the galaxy's jump point network. She's isolated herself, still processing the guilt of her Kree past and the people she hurt before she knew the truth. Then she uses her powers and teleports into a teenage girl's bedroom in New Jersey.
Kamala Khan—Ms. Marvel—has been manifesting light-based powers since the bangle she inherited awakened her abilities. When Carol switches places with her, Kamala is thrilled. She's meeting her hero! Carol is confused. This shouldn't be possible.
The third point of the triangle is Monica Rambeau, now a S.A.B.E.R. agent with her own light-based powers gained during the Westview incident. When she uses them, she switches with either Carol or Kamala. Three women, entangled across space, forced to coordinate their powers or trade places at the worst possible moments.
The villain is Dar-Benn, a Kree revolutionary wielding a bangle matching Kamala's. She's using the jump point network to steal resources from other worlds—air, water, the sun itself—to restore Hala, the Kree homeworld that Carol devastated when she destroyed the Supreme Intelligence. Dar-Benn blames Carol. She's not entirely wrong.
The entanglement leads to some of the MCU's most creative action sequences. Three heroes in three locations, switching constantly, having to trust each other's instincts. A fight through a Kree ship becomes a coordinated dance. A rescue mission requires split-second timing across light-years.
Carol faces her past directly. She freed the Kree from the Supreme Intelligence's control, but without their AI god, Kree society collapsed. Civil wars. Starvation. Billions dead. Carol saved them from tyranny and accidentally doomed them to chaos. Dar-Benn's rage is justified, even if her methods aren't.
The climax threatens Earth itself. Dar-Benn tears open a rift to steal Earth's sun, and Monica must sacrifice herself to seal it from the inside. She succeeds—the portal closes around her, and Carol can't reach her in time. Monica is gone, her fate unknown.
Kamala officially joins the superhero community. Carol commits to helping rebuild Hala instead of running from her past. Back on Earth, Kamala shows up at Kate Bishop's apartment in costume, pitching a team of young recruits—Cassie Lang among them. Young Avengers are coming.
The mid-credits scene answers where Monica ended up: she wakes in a parallel universe, at the bedside of a variant of her mother Maria—now going by Binary—who doesn't recognize her as her daughter. Beast examines her, explaining she's crossed into a reality parallel to her own, and mentions that "Charles" wants an update. The MCU's X-Men door is open.