Santa doesn't want to retire, but rules are rules and he must train someone to replace him. The lucky winner, to be chosen from among millions of children, must be named Nicholas, be an orphan and have a pure heart. On the other side of the planet, there is a little boy who is a perfect match, but his lack of self-confidence and fear of heights make him a poor contestant. Will Santa agree to step down, and help his apprentice take his place?
Years before the Arkham incidents, the neophyte Dark Knight finds himself the target of an open murder contract courtesy of Black Mask that draws eight of the world's deadliest assassins and a new criminal named The Joker.