Sources for letters credit are The Marvel Comics Index (Olshevsky 1981), The Official Marvel Index to the X-Men (Olshevsky 1987), The Official Marvel Index to the X-Men (Ward 1994), and Official Index to the Marvel Universe (Vandal et al. 2009).
The X-Men [Professor X; Cyclops; Marvel Girl [Jean Grey]; Iceman; Angel; Beast]; The Stranger (1st); Brotherhood of Evil Mutants [Magneto; Mastermind; Toad; Quicksilver; Scarlet Witch
Synopsis:
Xavier detects an exteremely powerful entity that has arrived on earth and sends the X-Men to investigate; The Stranger tries to acclimate himself to earth customs but runs across Magneto and the Brotherhood; The X-Men arrive on the scene and battle the Brotherhood but the Stranger leaves with Magneto and Toad in the conflict; Without a leader, Quicksilver and the Scarlet Witch decide to return home to Central Europe; The X-Men encounter the Stranger once again and Xavier realizes he is an alien; The Stranger explains that he has been collecting mutants from across the universe and takes Magneto and Toad away with him into space.