The first trailer for Batgirl: A Matter Of Family shows Batman wasn't invited to the showdown between Batgirl and The Joker.
The story add-on to Arkham Knight stars Batgirl on a night when The Joker kidnaps Commissioner Gordon and holds him hostage at the Seagate Amusement Park. With the help of Robin, Batgirl must fight against the crazy clown and his sidekick Harley Quinn to save her father from The Joker's crazy antics.
The Batgirl DLC will cost $6.99/£5.79 and is being developed by WB Games Montréal, the creators of Batman: Arkham Origins. If you own the Batman: Arkham Knight Season Pass, you'll be able to download the content on July 14th, otherwise it will be sold seperately a week later on July 21st.
Enjoy the trailer: