It's open season on Harley Quinn when her explosive breakup with the Joker puts a big fat target on her back. Unprotected and on the run, Quinn faces the wrath of narcissistic crime boss Black Mask, his right-hand man, Victor Zsasz, and every other thug in the city. But things soon even out for Harley when she becomes unexpected allies with three deadly women -- Huntress, Black Canary and Renee Montoya.