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.

In search of a nemesis, Harley goes after Batman, but ends up with an adolescent Robin, making her the laughing stock of the criminal underworld.

After a falling out with her crew, Harley heads back home to Bensonhurst, where her doting mother waits for her... and her deadbeat dad, who’s more dangerous than anticipated.