A strange storm stirs outside of the Institute. The X-Men head outside to check out the weather abnormally and find themselves faced with their most feared enemies.
This turns out to be a nightmare that Xavier is having and he can’t wake up from it. While monitoring Xavier’s condition, Beast finds that Xavier’s vital signs are dropping despite the fact that he isn’t physically harmed. Jean is unable to reach Xavier telepathically to wake him from his nightmare. An anxious Cyclops watches helplessly as Beast and Jean try to save Xavier.
Xavier’s dream shifts to that of his mother and his X-Men safe and sound in perfect world. But Xavier senses that something is amiss. His mind shifts now to the Astral Plane. While wandering through the cosmos of the mind, he drifts toward a talking bright light.
Jean calls out telepathically to Xavier. This time Xavier hears Jean, but is still drawn toward the talking light. The voice of the light brings up his memories twenty years back in Egypt. Xavier first met another psychic known as the Shadow King, and battled and imprisoned the Shadow King in the Astral Plane to save the children under his tyranny, among which is Storm.
Having met a mutant who would exercise his power for his own selfish means against the normal human race, Xavier felt it was his duty to form the X-Men to educate mutants on using their abilities for good and to protect the human race from mutants who threaten them. Xavier believes that humans and mutants can “co-exist”.
The talking light reveals himself to be the Shadow King, “manipulating and luring” Xavier, seeking to imprison Xavier so he can escape the Astral Plane. Xavier calls out to Jean for help. Suddenly Xavier awakens, and Beast, Jean and Cyclops think Xavier is alright.
Storm, Wolverine and Jubilee are attacked by their enemies. Storm senses the presence of the Shadow King. The security alarm goes off but as Beast discovers that there isn’t a physical security breach, the Shadow King reveals to the X-Men that he had taken over the body of Xavier after imprisoning Xavier on the Astral Plane.
Jean, having contacted Xavier, travels to the Astral Plane to save Xavier. The three telepaths battle on the Astral Plane: Jean and Xavier against the Shadow King. Jean and Xavier successfully put the Shadow King back into his Astral Plane prison and return to their human bodies.