Book excerpt: The Dark Knight's greatest enemies have all simultaneously escaped from Arkham Asylum and are preying on Gotham City. With his city under siege, Batman pushes his body to the limit as he takes on The Joker, the Mad Hatter, Poison Ivy, Killer Croc, The Riddler and the Scarecrow. But things get much worse when Bane, the man behind all the madness, confronts an exhausted Batman-and breaks his back..