The X-Men's world goes up in flames as the most incendiary mutant crossover of all begins! X-Factor, the New Mutants, the newly-minted X-Terminators and even Power Pack all feel the heat as the Machiavellian geneticist Mr. Sinister and the demon lord N'astirh set their respective sights on Cyclops' wife, Madelyne Pryor! The New Mutants' Illyana Rasputin may be lord of Limbo, but how long will that uneasy crown last when Limbo's demon hordes invade New York? COLLECTING: POWER PACK (1984) 40, 42-43; X-FACTOR (1986) 33-36; X-TERMINATORS 1-4; UNCANNY X-MEN 239-240; NEW MUTANTS (1983) 71-72