Thanos won't rest until he possesses the one weapon that will give him dominion over the entire cosmos: the mind of young Reed Richards! In the year 1483,

the alchemist supreme called Diablo embarks on a quest to transform the
world - literally; only the time-tossed FF stands in his way! And underground,
the macabre Mole Man returns to menace his former students! Plus: Back on
Terra Firma, it's the Fantastic Four versus X-Men in an Ultimate blowout!

Collecting Ultimate Fantastic Four #33-41 and Annual #2, Ultimate Fantastic
Four/X-Men, and Ultimate X-Men/Fantastic Four - written by Mike Carey;
and illustrated by Mark Brooks, Pasqual Ferry, Stuart Immonen, Frazer Irving
and Leinil Yu.