Batman finally knows who killed Vesper Fairchild, how they did it, and why they did it. And he needs the help of those close to him to bring the killer down - and to get this, he must first reconcile with them. Most of the legwork had been carried out by Batgirl, Nightwing, Alfred, Oracle and Robin, but for the first time everything is assembled:
Lex Luthor has been in constant conflict with Bruce Wayne since No Man's Land, and Wayne's opposition to his presidency made him decide to get rid of this irritation and pay for someone to perform a character assassination on the man. Through an agent known as Amherst, one of the world's top assassins was hired - David Cain, who also happens to be Batgirl's father and to have trained a young Bruce Wayne. Knowing of Wayne's other life, Cain decided to carry out the crime in a way which would expose his secret identity, or at worst create discord between him and those around him. For a time he succeeded, but now they must go after him - preferably without Batgirl.
However, when they find him, they instead find a series of doubles, and the real deal shows up at the Batcave and attacks Oracle - he had access to their communications channel. Thankfully, Batman had anticipated this, and is waiting in the shadows to take him on. Cain reveals his utter contempt for Batman/Wayne and tries to make him into what Cain is - but Batman refuses to go over the edge into unnecessary violence, and Cain soon hands himself over to the authorities. Luthor is not pleased, particularly because he cannot locate agent Amherst. Perhaps this is because he is in Arkham Asylum under a different name.