Since the discovery that the Terrigen Mists-the key to unlocking an Inhuman's hidden potential and powers-are LETHAL tomutants, the X-MEN and INHUMANS have been locked in a cold war. But as the Terrigen seeps into the Earth and reaches anirreversible tipping point, the X-Men are spurred into action to ensure the future of their species! And for Jean Grey and Fantomex,this means taking out of commission the Inhumans' deadliest weapon: Karnak!COLLECTING: ALL-NEW X-MEN 17-20, ANNUAL 1