In a clip from Batman: The Killing Joke (via this week's DC All Access), Batman comes to Arkham to get the skinny on his relationship with the Joker. He knows that their thing will eventually end with one or the other dead and hope to appeal to some decency inside Joker's warped mind. But it seems the Joker isn't even there.
The clip, featuring the voice of Kevin Conroy, begins at 3:57 of the video:
Batman: The Killing Joke comes to digital on July 26th and to disc on August 2nd.