What it’s about: After breaking up with The Joker, Harley Quinn seeks to turn over a new leaf by helping a group of vengeful women defeat the sadistic Gotham City crime boss, Black Mask.

Harley Quinn began as Dr. Harleen Quinzel, a psychiatrist at Arkham Asylum tasked with studying the Joker. The more she learned about the Joker, the more enamored with him she became, to the point ...