E Is For Extinction - Plot

Plot

As a new generation of mutants begins maturing across the globe, a long-lost Master Mold A.I. and Sentinel production facility in the jungles of Ecuador is uncovered by a mysterious woman called Cassandra Nova. She uses the last surviving relative of Bolivar Trask to gain control of the wild sentinels and has the man order the Sentinels to massacre the entire population of the mutant nation of Genosha. However, Cassandra Nova's presence shows up on the newly created mutant detection machine Cerebra, created by Beast, leading to Cyclops and Wolverine finding Cassandra and defeating her. But it's too late, as the nation of Genosha falls to the deadly might of the Sentinels and nearly the entire population of the island state is killed off.

As the X-Men search the rubble, they find former X-Men villain and teacher Emma Frost as one of the survivors, having survived the Sentinel onslaught thanks to her body undergoing a new secondary mutation. At the X-Mansion, Beast investigates the biological origins of the powerful enemy they have just captured, while also revealing the possibility of mankind's genetic extinction within the next few generations. When Cassandra suddenly overcomes her imprisonment and effortlessly makes her way to Cerebra (in order to take over Charles Xavier's mind), Emma Frost (who moments before the battle began had left the X-Mansion, intent on revenge against humans for the genocidal Sentinel attack on Genosha) shows up again to snap Cassandra's neck. But Emma arrives too late, as Cassandra has swapped bodies with Xavier and shoots him (now in Cassandra's body) to keep Xavier from revealing what has just happened.

Days pass; Jean Grey and Cyclops reflect upon the marital problems that have popped up due to Cyclops's post-traumatic stress disorder (brought on by Apocalypse possessing Cyclops's body for over a year) when they turn on the TV and see "Xavier" out himself as a mutant on live television.