After last issue's battle, the X-Men are worried that the comatose Xavier might never awake. Iceman, who still considers Lorna his girlfriend, angrily notices that Havok seems to be becoming closer to her, but Cyclops stops their argument. Acting on a hunch that Xavier might know how to cure himself, Beast fetches the Professor's mind probe, which can read surface thought, but all he gets is an image of Xavier's head urging them to find the Hulk. When Jean tries a telepathic probe, she likewise receives an image of Hulk and nothing else. Deducing it is the Hulk's alter ego scientist Bruce Banner, that the Professor means, the X-Men set off to find him, leaving behind Havok to protect Xavier. When Lorna elects to stay too, an angry Iceman insists on doing likewise.
Following news reports, the others find the Hulk in Las Vegas, and after a short fight, Jean telepathically subdues him, triggering his change back into Banner. The Army, led by Major Glenn Talbot arrives as the X-Men question Banner, who recalls corresponding with Xavier and building a gamma ray device to cure mental exhaustion based on their discussion. He tells them that it is at one of his secret labs, but Talbot refuses to let him leave so he can take the X-Men to it. The stress of an innocent man's life being dependant of him triggers Banner's transformation, and the Hulk bounds away, pursued by the X-Men. He stops in the desert to fight them, but their battle reveals Banner's hidden lab. Quickly retrieving the device, The X-Men leave the Hulk in peace. Racing home, they use the device to cure the ailing Professor.
Note: This is the last original story of the first X-Men comic book.