Nine months after the events of Arkham City, and the foiling of her revenge plan, Harley was approached to by Scarecrow to join his alliance to destroy Batman and take the city for themselves. She had no interest in Scarecrow's larger games, but joined in order to avenge the Joker's death. Grief-stricken and vengeful, Harley brutally reasserted control of Joker’s gang as it threatened to fragment after his death. Freed from Joker’s domineering personality, Harley became a dangerous, and unpredictable new force in the Gotham City underworld.