In this painted graphic novel, the inmates of Arkham Asylum have taken over Gotham`s mental illness detention center on April Fool`s Day and demand Batman in exchange for their prisoners. Accepting their demented challenge, Batman is forced to live and endure the personal hells of the Joker, Scarecrow, Poison Ivy, Two Face and many other of his sworn enemies in order to save the innocents and retake the prison. During his run through this absurd gauntlet, the Darknight Detective`s own sanity is in jeopardy.