Vers is a Kree warrior, a member of the empire's elite Starforce and one of its fiercest soldiers. Under the tutelage of her superior officer Yon-Rogg, and with guidance from the Kree's leading AI, the Supreme Intelligence, she is capable of channeling energy into destructive blasts from her hands. Nonetheless, her life is not quite ideal; she suffers from amnesia, having no memories from before meeting Yon-Rogg and being haunted by visions of lying on a battlefield, an older woman standing nearby with a blaster in hand...
One fateful day, Vers is given a mission: to extract an intelligence officer captured by the Skrulls, a race of shapeshifting aliens with whom the Kree have long been at war. The mission goes awry when Vers finds the intelligence officer, only to discover that he is actually a Skrull in disguise. The Skrull captures Vers and has her brought onboard a carrier ship to probe her memories. The probing unearths memories of a life Vers cannot remember: a childhood and military career on a planet completely alien to her, and the name of the woman who appears in the recesses of Vers's mind: Dr. Wendy Lawson. Eventually, however, Vers manages to break free and escape to the planet the Skrull ship is orbiting.
That planet is known to its native inhabitants as "Earth".
Vers jury-rigs a communicator using Earth communications equipment and relays her location to Yon-Rogg to request an extraction. It is at this point that she is approached by Nick Fury, an agent of S.H.I.E.L.D. As Vers explains the situation with the Skrulls, the two unlikely allies find themselves ambushed by two of the selfsame alien menaces. One manages to evade Vers, but Fury manages to kill the other.
Afterwards, the two join forces to search for the truth behind Wendy Lawson; she is tied to a top-secret project of the American military known as "Pegasus". The goal of the project was the development of an experimental new jet engine, but the project resulted in failure, along with the deaths of Lawson and the jet's test pilot. When the two go to the black site where "Pegasus" was developed, they find evidence that Vers was the test pilot who was supposedly killed.
There is little time for them to ponder how this could be, however: S.H.I.E.L.D. had been infiltrated by a Skrull passing as Fury's boss, and they have come to capture them. Vers and Fury manage to make their escape in a cargo jet with the files they found on "Pegasus" and with Lawson's stowaway cat, Goose, whom Fury takes a shine to. They set their next destination: Louisiana, the home of Maria Rambeau, the last person to see Lawson and the test pilot alive.
Upon meeting Maria and her daughter, Monica, Vers learns the truth behind her missing past: her real name is Carol Danvers, and she was a US Air Force pilot and Maria's best friend. As they catch up, they are approached by two Skrulls. One of them, the general Talos, explains that he has come not to fight, but to help Vers fill in the holes in her memories. He provides a CD with a recording from the black box of the experimental aircraft, thought lost in the crash. With this, Vers realizes the truth behind her vision:
While testing the craft with Lawson as co-pilot, Carol Danvers came under attack by an alien craft. The experimental jet crashed, with Lawson badly wounded, her blue blood betraying her alien nature. Lawson explains that her real name is "Mar-Vell", and she was a Kree scientist working against her own empire to aid their mortal enemies, the Skrulls, who are actually victims of the Kree's brutal expansionism. Pegasus was an attempt to create a faster-than-light ship that could help the Skrulls find a new homeworld, but in the Kree's hands, it would only make them more dangerous. Thus, the core must be destroyed.
Before Mar-Vell could destroy the core, though, she was shot and killed by Yon-Rogg. Carol took up the blaster Mar-Vell held and shot the energy core of the Pegasus craft, causing it to explode. The energy from the destroyed core washed over, and was absorbed into, Carol's body, granting her its immense power while also causing her to lose her memory...
As Carol's memories of her past are finally made whole, Talos explains that their one hope of finding a new home lies in Mar-Vell's laboratory, but they haven't been able to find it. Carol manages to locate it, however; the coordinates Mar-Vell gave her didn't point to a location on Earth, but rather, in Earth's orbit. After modifying the cargo jet to take them into space, Carol, Maria, Fury, and Talos make their way to Mar-Vell's laboratory, a Kree Imperial cruiser, along with Goose, who creeps out Talos for some reason...
Aboard the lab, the group make two surprising discoveries: the Tesseract, an artifact that was used as the power source of the Energy Core, and a large group of Skrull refugees, including Talos's wife and son. Unfortunately, the Kree are not far behind. Yon-Rogg captures Carol and forces her to interface with the Supreme Intelligence to force her back into compliance. Carol, however, overpowers the Supreme Intelligence and fights back against her former squad as Fury, Maria, Talos, the refugees, and Goose (revealed to be a dangerous Flerken) escape back to Earth with the Tesseract. At Yon-Rogg's behest, a fleet of ships with ballistic missiles, led by Ronan the Accuser, arrives to bomb Earth to exterminate the Skrull presence. Carol easily destroys the missiles and cripples the fleet, forcing Ronan and his men into retreat.
Carol confronts and subdues Yon-Rogg and sends him back to the Kree capital with a warning for the Supreme Intelligence. She then says her farewells to her old and new friends on Earth, leaving a modified pager with Fury in case of an emergency, and departs with the Skrulls to find them a new homeworld. Later, in his office, Fury reviews the Pegasus file and takes inspiration from Carol's Air Force callsign, "Avenger", for an idea to bring together a group of remarkable people to serve as the Earth's mightiest heroes...
That was in 1995.
Several years later, the Earth has radically changed, but not for the better. Earth's population has been halved, all thanks to a mad tyrant with the power of a god. Steve Rogers, Natasha Romanoff, Bruce Banner, and James Rhodes have found a modified pager where Fury was last seen before his disappearance. They couldn't find where it was broadcasting to, nor to whom, before it suddenly shuts off. As Natasha prepares to look for answers, she turns around to see Carol Danvers standing right nearby, with a burning question: