Apocalypse's long-prophesied ascension begins! As Professor X grows paranoid and withdrawn, the X-Men split up... leaving only a small team to aid a friend. And when Apocalypse's newest Horseman of Death strikes, an X-Man will perish! But not everything is as it seems, and as the team realizes the full scope of Apocalypse's scheme, it may be too late! Only the Twelve, a gathering of mutants foretold to save the world, might turn the tide... but Apocalypse plans to use them to become a god! Who will make the ultimate sacrifice to prevent the Ages of Apocalypse from becoming a horrifying reality? Collecting: Uncanny X-Men (1981) 371-380, Annual '99; X-Men (1991)91-93, 94 (A Story), 95-99, Annual '99; X-Men Unlimited (1993) 24(A Story), 25-26; Gambit (1999) 8-9; Astonishing X-Men (1999) 1-3; Wolverine (1988) 145-149; Cable (1993) 71-78; X-Man (1995) 59-60; X-51 (1999) 8; X-Force (1991) 101; X-Men 1999 Yearbook