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.