Margot Robbie as Dr. Harleen Quinzel aka Harley Quinn is PERFECTION in that role. She was made for it. Her backstory is explained and fast forward to the present as her and Joker broke up. Which means as his now ex-girlfriend she has no protections from the people she's tortured or other mobs like Roman Sionis (Ewan McGregor). At the same time a woman is killing men with a crossbow (Mary Elizabeth Winstead), Detective Renee Montoya (Rosie Perez) is trying to track down the crossbow killer and capture Harley Quinn, and Dinah Lance aka Black Canary (Jurnee Smollett-Bell) gets a promotion from Roman's club songstress to his driver. The storylines all merge together when a diamond is missing that could help all three women...stole by an orphan pickpocket named Cassandra Cain (Ella Jay Basco).
My problem is Ewan McGregor and Chris Messina (as Roman's right hand) acted over the top. Their characters WEREN'T over the top like Harley Quinn, but Ewan would scream or Chris would smirk. It just didn't feel like these characters were in their range. They were ACTING whereas Margot just WAS Harley Quinn, accent and all.
Great movie directed by Cathy Yan and written by Christina Hodson. I can totally see a Joker cross over. Worth seeing in the theater.