The chart-topping super-team Joss Whedon and John Cassaday return for more Astonishing X-Men! Strap yourselves in! After the shocking and brain-smashing events of the previous three arcs - Gifted, Dangerous and Torn - the X-Men are off to protect the Earth from its destruction at the hands of the Breakworld. And when it's all over, nothing will ever be the same! In this fourth and final arc of Astonishing X-Men, mastermind Joss Whedon and award-winning artist John Cassaday prove they are more than Astonishing: they are Unstoppable.