Determined to become one of the vaunted Legion of Doom, Harley attempts to make a big splash by crashing one of their criminal enterprises with the help of her BFF, Poison Ivy.

Harley gets an invite to the Legion of Doom’s prospective members party, but Ivy learns that she's the one they're really interested in.

Now a member of the Legion of Doom and The Joker’s equal, Harley finds herself spending time with him. Will she slip into her old ways?

Harley must rescue Ivy from the clutches of Scarecrow, who’s trying to harvest her pheromones to make a super toxin that turns plants into sentient monsters.

In the season finale, Harley has her final showdown with the Joker, when [spoilers] [spoil] [spoilers]. Will they [spoiler]? Maybe. But you can bet they [spoiler]!