Play Vault's Jonesy:
"Rocksteady have released a meaty bit of DLC to keep their baying fans sated for a while. This time however they mix the formula up a little by allowing us to play as Robin. That’s right he may have made a simple cameo appearance but the Tim Drake version of Robin takes the main mantle for most of the Harley Quinn’s Revenge.
The plot is more of an epilogue of to Arkham City and you will find yourself constantly switching between Robin and Batman as it recounts Harley’s plan to exact revenge on the Caped Crusader and the Boy Wonder due to the events of the main game."