X7 opens with Kamui staring in shock at the remains of his aunt as her body splits open before them. Her head lands near his feet, and he falls to the ground in grief. Fuuma stands watching, not knowing what is happening, or how to help the situation. As Kamui cries, a voice comes to him calling his name. He looks up and sees Tokiko's soul, which hugs him fondly and tells him not to be sad because this was her fate. She tells Kamui to take the sacred sword to CLAMP Campus, where it will be safe until he needs it. She then gives him one last hug and vanishes before them.

It's at this point that all hell breaks loose, Kotori enters the room, and upon seeing Tokiko's dismembered remains, is suddenly overcome with "forgotten" memories of her own mother's horrible, yet similiar death. She runs towards Tokiko's head, but Kamui stops her. Like glass, her mind shatters, unable to deal with the flood of emotions. She breaks free from Kamui and stumbles towards the head. Kamui turns to Fuuma for help, but his friend doesn't seem to be listening. He grabs Kamui by the wrists and begins once again to chant his father's last words. Kamui mangaes to turn and face him, and is greeted by Fuuma's murderous stare. Kotori picks up Tokiko's head and the room plunges into darkness around her.

She looks down and realizes that it is her own head she is holding and that she is now underwater. She hears a voice calling to her and turns to see a mermaid, her mother. Kotori is overjoyed to see her mother, but not to hear her mother's next words. Her mother explains that she is now in the ocean of sin, and she is there because she refused herself the love of the person whom she truly loved, Kamui's mother Tohru. Kotori calls her a liar, and she vanishes. The floor opens underneath her and Kotori is falling again. She begs for Kamui or Fuuma to help her when a wire comes from the sky and pulls her up through the water's surface. She finds herself in Kakyou's bedroom. Kakyou tells her that her heart lead her to him.

Kotori tries to open the curtains around Kakyou's bed and the room dissolves once more. She finds herself standing on the shoreline, seagulls everywhere. A man approaches her and identifies himself as Kakyou. Kotori is confused, even more so when from a ball of light nearby Kamui emerges, with one angel wing and one bat wing. Kakyou tells her that an earthquake is about to take place at Nakano. Kotori suddenly sprouts glass-like wings and flies into the sky.

Back at Togakushi Kamui is having a hard time fending off Fuuma. Lightening splits the sky, and Fuuma suddenly comes to his senses. As they try to figure out what's going on, they both hear Kotori's laughter behind them. They turn to look and see her holding Tokiko's head and smiling. (She is quite insane by this point.) She tells them that one of the seven dragons is about to break free and that there will be an earthquake. As if on cue, the temple shakes with thunder as the ground roars in protest. Fuuma rushes to protect his sister and best friend.

Across the city the Dragons of Heaven and Earth feel the quake's power. At the telephone booth Arashi collapses, Sora drops the phone and pulls her out of the booth while protecting her from the falling glass. In the subway Saiki protectively helps Yuzuriha stay standing as the train de-rails. At Asuka and FLOWER, Seiichirou and Karen look up in wonder at the power they are feeling. At a nearby park Kusanagi snaps alert, while Subaru almost drops his cigarette. At Sunshine 60, Nataku awakens. Yuuto and Satsuki watch the destruction from a helicopter pad above the Tokyo Government offices. Hinoto collapses into a dream, Kanoe follows her, and Seishirou smiles, knowing he has caught Subaru's attention.

As both Kanoe and Hintot argue in their dream about the future of Earth and of Kamui, they are surprised when another dream invades their own. For a brief moment, Hinoto sees Kakyou in his curtained bed and wonders if the dream is a "yume-mi" dream, and if the yume-mi is of the Dragons of Heaven. Kanoe wonders the same, but if he is a Dragon of Earth.

At Togakushi Fuuma quickly checks to see if Kotori and Kamui are all right. Kotori tells them that everything happened as Kakyou said. Kamui, seeing the insanity in her eyes, begs for her to look at him but Kotori just hugs Tokiko's head and tells them about the ocean where their mother was a mermaid. She mumbles something about Kamu's twin star and then collapses.

Across Tokyo the Dragons of Heaven pull themselves together. Sora and Arashi decide to find the cause of the quake. Saiki and Yuzuriha abandon the subway in pursuit of the same, while Subaru, sensing the Sakurazukamori's presence, runs off to find him.

Deep in the dream, Hinoto and Kanoe watch the dream that Kotori has passed through. The winged Kamui's, the shattering of earth, and Kotori's sacrifice in shattering herself. (See X vol.6 for details)

At the end of X7, there is a special character feature on Satsuki, why she cannot stand humanity as it is now, her initial experimaents with BEAST, her learning of Kamuo's return, and BEAST's command to kill her co-workers. (I'd be more detailed than that, but I really can't be without going into the dialogue)