Miss Harley Quinn hasn't had a good time of it lately.  Ever since the end of Batman Arkham City she's been missing her main squeeze, and plotting her revenge.  Luckily for us she doesn't have to wait too much longer, because Harley Quinn's Revenge, the final DLC for the game, will be out on May 29th.  For those who haven't yet picked up Batman Arkham City, you can also get the Game of the Year Edition that day, which will include all the DLC from the game, so you can experience the entire story from beginning to end. 

For the rest of us who already have the game, Harley Quinn's Revenge Pack will be available for $9.99 on PSN, and 800 Microsoft Points on Xbox Live Arcade.  As the video says, payback is a b---, and so is she.