"Night of the Demon!"
Cyclops wanders through the woods in a melancholy mood after the death of his team-mate, Thunderbird. Scott's frustration is fueled by the fact that Thunderbird's demise was pointless and unnecessary, and expedited by an act of machismo.
In a moment of irresponsibility, Cyclops unleashes the full force of his optic beam. Unbeknowest to him, his blast ruptured open a gateway to a Demon dimension.
The new X-Men's training sessions aren't going too well. Wolverine's unpredictable nature and suspect temperament make him a hazard to the health of his comrades-in-arms.
The X-Men are introduced to an old friend of Professor Xavier, Moira MacTaggert.
At a secret mountain range installation, a scientist named Stephen Lang voices ideas which sound chillingly like a Final Solution for Mutants. When his 'Project Armageddon' is threatened with shutdown by Washington, Lang takes drastic action.
At the X-Mansion, a one-eyed Demon appears. All of the X-Men attack it with no effect until Wolverine cuts loose with his claws. For the first time the team witnesses Berserker Rage. Even then, that is not enough to destroy the Demon.
Xavier gleans information from the Demon's own mind as to means of defeating the extra-dimensional beast. He sends Storm to the site where Cyclops had unwittingly freed the Demon. Ororo is ambushed by more creatures from the gateway.
It is only Storm's innate fear of being trapped in the dark that allows her the strength to dispatch the demons assailing her. One powerful energy bolt destroys the monument that the evil has flooded through to this world. The one-eyed Demon vanishes in a puff of smoke.
First appearance of Moria MacTaggert.