Uncanny X-Men, Vol. 1 #149 (1981)

And The Dead Shall Bury The Living!
Professor X suspects Magneto is alive and planning... something. He sends the team to investigate his last known base, and they find it empty of all but a potent defender. Meanwhile, Cyclops and Lee Forrester are enjoying Magneto's hospitality in his new home.
Release Date: 1981