During a fight with Juggernaut, Cyclops imagines Jean at the scene. His hesitation to attack jeopardizes the mission. Not wanting to let anyone get hurt on future mission, Scott decides to leave the team. Emma offers to help him remove his memories of Jean so he will not be a distraction to the team.
After thinking about it, Scott allows Emma to look into his memories. Some are painful, like losing his parents to a plane crash and having his brother adopted with a foster family because he had been in a coma for two years. Xavier rescued him from an orphanage and trained him to be an X-Men. Scott met Jean when Xavier took him to meet the Greys and officially enroll Jean as a student at the Institute.
A powerful mutant in the making, Magneto fought to convince Jean to join his side. In the end, Jean was the last X-Men standing in the fight against Magneto. Jean was able to force a bus thrown at her by Magneto, telekinetically back at Magneto. Cyclops had lost his visor, and for a moment, Jean is able to hold his optic blasts back telekinetically. Trusting Jean, Cyclops aims directly at Magneto and takes him down. Magneto admits defeat and retreats. By then, Cyclops and Jean have grown close and are seen to share a kiss after the victory.
But the happy memories make way for angry ones when the arrival of Wolverine challenges Jean’s affections. Scott lashes out at Wolverine, who promised Jean he would not hurt Scott. This brings him back to the day Jean disappeared. Wolverine had decided to leave and shortly after the explosion happened. Digging deeper into the memory, Scott and Emma discover that Jean’s Phoenix manifestation was the cause of the explosion.