Fantastic Four #49 (2001)

Abraxas - the conclusion! It's the end of Carlos Pacheco's grand run! Having collected the Ultimate Nullifier and confronted Abraxas - who stands poised to destroy the Multiverse - the Fantastic Four fear it's all for naught. With the end of time near, they turn at last to the one force capable of confronting this ultimate evil... but you'll have to buy this comic to find out what that force is!