| Issue | #12 |
| Published | August 1987 |
| Cover Price | 1.00 USD; 1.25 CAD; 0.40 GBP |
| Pages | 36 |
| Editing | Ann Nocenti; Terry Kavanagh (assistant editor); Archie Goodwin (original material) |
| Genre | Superhero |
| Pencils | Arthur Adams |
| Inks | Al Williamson |
| Reprinted | in Incredibili X-Men, Gli (Edizioni Star Comics, 1990 series) #22 |
| Characters | Magneto |
| Genre | Superhero |
| Pencils | Arthur Adams |
| Inks | Al Williamson |
| Characters | FEATURE: X-Men--Professor X; Cyclops; Phoenix [Jean Grey]; Storm; Wolverine; Colossus; Banshee; Nightcrawler; GUESTS: Moira MacTaggert; Multiple Man; Misty Knight; VILLAIN: Magneto; CAMEOS: Eric the Red; Havok; Polaris; Lilandra; Corsair; Ch'od |
| Synopsis | The X-Men head to Muir Island to make sure everything is fine there and discover that Eric the Red has grown Magneto back to adulthood (and Maggie isn't a very happy camper). |
| Genre | Superhero |
| Script | Chris Claremont |
| Pencils | Dave Cockrum |
| Inks | Sam Grainger |
| Colors | Evelyn Stein |
| Letters | Bruce Patterson (p. 1-3, 7-20); Ken Lopez (p. 4-6) |
| Reprinted | from X-Men (Marvel, 1963 series) #104; in Incredibili X-Men, Gli (Edizioni Star Comics, 1990 series) #22 [with the added pages] |
| Characters | Magneto |
| Genre | Superhero |
| Script | Chris Claremont |
| Pencils | John Bolton |
| Inks | John Bolton |
| Colors | Glynis Oliver |
| Letters | Tom Orzechowski |
| Reprinted | in Magneto: The Twisting of a Soul (Marvel, 1993 series) #0; in X-Men: Lost Tales (Marvel, 1997 series) #1; in Incredibili X-Men, Gli (Edizioni Star Comics, 1990 series) #22 |
| Characters | Cyclops; Storm; Wolverine; Colossus; Nightcrawler; Magneto |
| Genre | Superhero |
| Pencils | Dave Cockrum |
| Inks | Dave Cockrum |
| Letters | Dan Crespi |
| Reprinted | from X-Men (Marvel, 1963 series) #104 |
| Characters | Magneto |
| Genre | Superhero |
| Pencils | John Bolton |
| Inks | John Bolton |
| Notes | Back Cover |
| Reprinted | in X-Men: Lost Tales (Marvel, 1997 series) #1 |