Margot Robbie is said to be one of the greater factors around the "Suicide Squad" movie. However, it still seemed as if there could be something more for her to offer apart from being The Joker's sidekick.

A new film titled "Gotham City Sirens" has been confirmed, although the only actress with an affirmative role is Robbie as the enigmatic Harley Quinn. Casting is reportedly ongoing for her companions Poison Ivy and Catwoman. The Australian-born celebrity apparently prepares for the role even harder now than her first exposure through "Suicide Squad."

According to a Reddit user that dug up Robbie's recent reading material through decoding, the actress has her hands on the 2015 "Harley Quinn Valentine's Day Special." It was also said that Robbie could be reading an entire collection of the novel, namely "Harley Quinn Vol. 3: Kiss Kiss Bang Stab"-with both examples deemed perfect for research on the feisty DC female villain.

The "Harley Quinn" comics made from 2013 to the present were written by Amanda Conner and Jimmy Palmiotti. Both are responsible for the comedic stature of the character at present, giving her a new image to carry in the upcoming issues.

A synopsis for the "Harley Quinn Vol. 3: Kiss Kiss Bang Stab" from DC Comics stated, "Harley was certain she could have it all. She could be the world's best landlord, protect Coney Island from the scum of the Earth, woo Mason Macabre, work her day job as a psychiatrist, volunteer at the puppy shelter...but that's a lot of spinning plates, and eventually they're bound to start breaking! What happens when a psychopath cracks up? Is it possible for Harley to go even more insane?!"

Robbie's Harley Quinn first appeared in "Suicide Squad" in mid-2016. No official release date has been given yet for "Gotham City Sirens," nor is there any announcement for the other cast.