"I Am Not Now, Nor Have I Ever Been..."
Wolverine is revealed to have been a Skrull imposter since the events in X-Men (1991) #90.
Giant-sized anniversary issue.
The X-Men are called to Muir Island because one of their own has been killed, Logan is dead. Moira and Beast prepare to do the autopsy while Peter's brother recovers in the infirmary. The X-Men wait for the results but they are still not happy with the way Charles is acting and it all explodes. Charles blames Phoenix of mind controlling part of the team as the X-Men split into two factions, one following Charles and the other with Jean. The two sides battle through the facility in a test of loyalty but all is not as it seems. It's only a test as Charles explains his reasoning behind this mind game and it all ties into the autopsy of Logan. Logan is not Logan but a Skrull imposter and Charles had to test the X-Men to see if any of them were Skrulls. Something big is about to happen and Charles needs to know who to trust.