Reprints X-Men #20
"I, Lucifer"
Unus and the Blob have teamed up to commit crimes in the city while posing as the X-Men so they will face the blame. Another X-Men quits as Scott (aka Cyclops) leaves the team but as he runs away, he runs into the imposter X-Men doing their dirty deeds. While the X-Men fight Unus and the Blob, Lucifer attacks Professor X, trapping him inside his own mind as Jean reaches out to learn the story of how Professor X lost his ability to walk.