As the X-Men battle Mastermind and his hencemen, Xavier battles the unknown telepath in the dimensional rift. As Xavier is drawn deeper into the rift and feels like he is losing the fight, he hears Jean calling out to him, urging him not to give up the fight.
The X-Men defeat Mastermind’s henchmen. Yui’s assistants Riko and Kaga awaken to find the laboratory destroyed and make their way down to the fault. Beast tells them that they had been infected with the Daemon Hall syndrome and went “berserk”, causing some damage to the facility.
The X-Men find a huge machine in the fault. It is the device that has been blocking Xavier’s telepathy, as well as Cerebro’s ability to detect mutants in the Tōhoku area. In addition, they find a back room inside the fault that Mastermind had fled into. Emma explains to Riko and Kaga that the researcher they had known as Jun was Mastermind in disguise, who had infiltrated their facility to obtain an immense power held in the laboratory so he can use it rule humanity with. But Emma does not know what this power is, and questions Yui about it. Beast deduces that the answer to the Daemon Hall syndrome lies hidden in that room.
Before Wolverine can forcefully reveal the secret hidden in that room, Yui decides to tell the X-Men everything. Yui had collaborated with the U-Men. In exchange for the U-Men’s mutant suppressant (harvested from mutant organs), Yui built the U-Men a “mutant detection blocker” so they could “hunt mutants”, and a jamming device so the U-Men could access her facility. Beast adds that his investigations show that the power in the room is leaking, and causing the spike in the mutant activity. Emma wonders why Yui had not reached out to Xavier for help since they are friends, and going through immense lengths to keep her secret from everyone.
Hurriedly, they approach the room. Hisako experiences discomfort as the power is affecting her mutation. Inside, they find a boy, Takeo, locked up. Yui reveals that Takeo is hers and Xavier’s son. Everyone is shocked at the revelation. When Takeo's powers manifested, Yui closed her school for mutants and moved to the mountains to hide, and attempt to find a suppressant for Takeo. Only two of her loyal assistants, Riko and Kaga relocated with her to work on her research.
Yui brought in the U-Men when she found out that the suppressant can only be obtained from mutant organs. Unknown to all, the U-Men were in cahoots with the Inner Circle, a partnership that benefited both parties that wanted to kill more mutants. Through the U-Men, Mastermind discovered Takeo, whose omega-level abilities rivalled that of Jean’s. He disguised himself as Jun to get close to Takeo, and has been depriving Takeo of his suppressant for months to reactivate his powers. In addition, Mastermind has been manipulating Takeo’s mind.
Neuron, another Inner Circle leader, appears and instantly kills Riko and Kaga. Meanwhile, Xavier breaks free of the rift and heads for the laboratory. Mastermind and Neuron unleash the full force of Takeo’s power, causing chaos. Cyclops is the only X-Men standing after the Inner Circle has the rest of his team restrained.