Harley Quinn, now played by pop icon Lady Gaga, will return to the big screen in Joker: Folie à Deux. She succeeds Margot Robbie, who played the character in three different DCEU movies. But judging from the first trailer, this take on Harleen Quinzel will be somewhat different from the ones fans have known for over 30 years. Here’s how director Todd Phillips’ version of Harley Quinn differs from the traditional version we’ve come to know since she debuted in Batman: The Animated Series.

The Batman: The Animated Series Origin of Harley Quinn

Harley Quinn, in her original Batman: The Animated Series look by Bruce Timm.
Warner Bros. Animation

Harley Quinn was created by Bruce Timm and Paul Dini in 1992, as a sidekick/girlfriend for the Joker on Batman: The Animated Series. Thanks to a wonderful performance from actress Arleen Sorkin, who inspired the character in the first place, she became a fan favorite. By the end of the ’90s, DC incorporated her into the DC Comics universe proper. A year after her debut, Timm and Dini teamed up for the comic book Mad Love. This was the first origin story presented for Harley. It would later serve as the template for a 1999 episode of The New Batman Adventures of the same name.

Warner Bros. Animation

In her origin story, her real name was Harleen Francis Quinzel and she was the Joker’s therapist at Arkham Asylum. The name was a nod to her voice actress, Arleen Francis Sorkin. Harleen had gone to Gotham University under a gymnastics scholarship but also studied psychology. She hoped to write a book about a famous killer and make a name for herself that way. When she became a psychiatric intern at Arkham Asylum, she saw the Joker as her meal ticket. But the Joker manipulated her and told her lies. He made himself seem sympathetic and a victim of circumstance. She fell in love with him and he twisted her mind in the process. Ultimately, she helped him escape Arkham and became his willing accomplice, girlfriend, and literal partner-in-crime. Joker christened her with the name Harley Quinn, since her real name, Harleen Quinzel, reminded him of a harlequin.

DC Comics Adds to Harley Quinn’s Backstory

DC Comics

The writers at DC Comics kept this cartoon backstory largely intact. Later, they added an explanation for her enhanced strength and agility. Those powers were the result of a serum created for her by her sometime girlfriend Poison Ivy. It also made her immune to most toxins and poisons. Eventually, Harley broke free of the Joker’s abuse for good, and became something of an antihero. In DC’s New 52 reboot, DC added in the detail of the Joker pushing Harley into the same vat of chemicals that bleached his skin and drove him mad. The 2016 Suicide Squad movie, featuring Margot Robbie, incorporated this detail into her live-action origin story.

Lady Gaga’s Harley Is an Arkham Inmate, Not Joker’s Therapist

Warner Bros/Warner Bros. Animation

For the upcoming Joker: Folie à Deux, it looks like Gaga’s version of Harley Quinn will differ significantly. She’ll be another inmate at Arkham, not a therapist treating Fleck. Although, for all we know, she was a therapist once, just not his. Much like the comics, it looks like she will play a key role in breaking Fleck out of Arkham. Judging from the teaser, it appears she has more of an upper hand in the relationship than he does. She seems to be manipulating him more than the other way around. At least in one scene, Harley will sport her traditional red and black color scheme, which is a clear nod to the comics. We’re not even sure if her real name in this universe is Harleen Quinzel, as the name Arthur Fleck isn’t from the comics.

We’ll know for sure when Joker: Folie à Deux hits theaters on October 4.