E Is For Extinction - Part 3 Of 3 Beast and Phoenix search the ruins of Genosha for survivors of the mutant massacre. Under fifty tons of debris, Emma Frost (in her new shimmering diamond form) carries the dead body of one of her students, Negasonic Teenage Warhead. They return with Emma to the X-Mansion, where Beast explains that a Secondary Mutation allowed for Emma's organic diamond exoskeleton, his feline appearance and the return of Jean's telekinesis. Meanwhile the one responsible for the genocide, Cassandra Nova, is contained in a gravitational bottle. Beast describes her as a new species, aware of the Extinction Gene and a being who will instinctively try to wipe out the mutant race for dominance. It is at this moment, that Cassandra releases herself from her imprisonment and overwhelms the X-Men with her vast psionic abilities. She then activates Cerebra and threatens to extinguish every mutant mind on the planet. Emma Frost appears from behind and snaps her neck; but before Cassandra can heal herself, Professor X repeatedly shoots her. Much later, Scott and Jean discuss their stressed marriage, but are suddenly shocked as the Professor outs himself as a mutant on television and proposes to do away with masks.