The blockbuster final chapter of the first era of ULTIMATE X-MEN! The world was on the brink of destruction. Countless heroes died. The X-Men are gone. The true history of the X-Gene has been revealed, and now mutants have been branded as terrorists and are being hunted as criminals. But there is hope - in the form of an unlikely group of young heroes gathered together to save tomorrow. Who, or what, is Ultimate X? And in a world where fear and hatred run rampant, how will the X-Men return? Get ready for the war for mutant liberation, with Kitty Pryde as the figurehead for her people, on a collision course with…Jean Grey! Will the planet be torn apart when the mutant nations of Utopia and Tian clash? Or will that fate come at the hands of the world-eating Galactus?! A cataclysm is coming - for the X-Men and the entire Ultimate Universe! Collecting ULTIMATE COMICS X (2010) #1-5, ULTIMATE COMICS X-MEN (2011) #1-33 and #18.1, ULTIMATE COMICS WOLVERINE (2013) #1-4, CATACLYSM: ULTIMATE X-MEN (2013) #1-3, CATACLYSM: THE ULTIMATES' LAST STAND (2013) #4-5 and material from ULTIMATE FALLOUT (2011) #2-6.