Strap yourselves in folks. - It's Joss Whedon and John Cassaday's fourth and final arc on Astonishing X-Men. - 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. When it's all over nothing will ever be the same - No really we mean it! - Whedon and Cassaday prove they are more than Astonishing: They are Unstoppable!