After getting kicked out by the Joker once again, Harley Quinn roams the streets of Gotham when she bumps into eco-terrorist Pamela Isley, a.k.a. Poison Ivy. With Batman missing, they become known as the Queens of Gotham as they wreak mayhem throughout the city. However, when her old flame, Mista J, does not like her new friend she must choose between her romance with the Joker or her friendship with Ivy.