The unthinkable has happened as the X-Men find themselves reeling from the devastating events of Ultimatum. A band of humans have stolen Sentinel technology and attacked Xavier's mansion - killing any mutant they see! With the X-Men locked in battle with Magneto, can anyone save these students? Their greatest hope might rest in the hands of their worst enemy as the Weapon X program returns! Also, Ultimatum has hit the planet hard and the Baxter Building was ground zero. Johnny is still missing. Dr. Storm is dead. And Reed has taken off to parts unknown. Sue's life hangs in the balance and rests in the hands of untested pilot Ben Grimm, a.k.a. The Thing, and Dr. Arthur Molekevic, now better known as the megalamonical Mole Man. This title collects "Ultimate X-Men", numbered 98-100 and "Ultimate Fantastic Four", numbered 58-60.