The upcoming DC superhero adaptation Birds of Prey: And the Fantabulous Emancipation of One Harley Quinn is set to smash into theaters in February 2020, and while little is known about the film’s plot, it’s clear the story revolves around one key character in the Batman universe: Cassandra Cain.

Created by Kelley Puckett and Damion Scott in July of 1999, Cassie Cain is one of several DC comic book characters to take on the mantle of Batgirl. According to the movie’s synopsis, Cass (played by Ella Jay Basco) is a young girl who finds herself under the protection of Harley Quinn (Margot Robbie). Why the movie’s villain Roman Sionis (Ewan McGregor) wants her is also a mystery. Birds of Prey’s promo posters, TV spot, and movie trailer show very little about her character, but these tidbits alone suggest her character in the film will be quite different than her comic book counterpart.

For starters, when the character was initially introduced in Batman #567 she was mute, illiterate, and lacked social skills most people take for granted. The daughter of world-renowned assassins Lady Shiva and David Cain, Cassandra (or just Cass for short) was trained to be a living weapon and was never taught the ability to speak, out of a belief that it would interfere with her fighting prowess. Groomed to serve as a bodyguard to DC mega-villain Ra’s al Ghul, she killed her first victim at the tender age of 8.

Though her origins have been tweaked over the course of 20 years, her original pre-Infinite Crisis introduction to comics took place during the events of No Man’s Land,where Gotham was under quarantine after being hit by a city shattering earthquake. The two-issue Mark of Cain story gave readers a fast-paced backstory to a character that would go on to become one of the Bat-family’s most beloved (but often underutilized) characters. Mark of Cain depicted Cassandra as a mysterious courier for Barbara Gordon in the lawless wastelands of Gotham. When she saw her estranged father about to assassinate Barbara’s father James Gordon, Cass stepped in front of David Cain’s sights and saved the commissioner’s life. This immediately put her on the Dark Knight’s radar, who quickly realized that she spoke no language other than violence.

Eventually, through the tutelage of Batman and Barbara Gordon, Cassandra Cain learned to speak and took on the role of Batgirl (Barbara had already hung up her cape and cowl at this point, operating under the hacker code-name Oracle). Her crime-fighting outfit was quite different than that of her ginger predecessor, too. Her mouth and eyes were concealed, giving the costume a stealthier, ninja aesthetic. With her position firmly cemented in DC lore, Cass Cain went on to become the first Batgirl to star in her own comic series, which lasted for six years and 73 issues. This was an impressive achievement at the time, and even more notable for a woman of color in a mainstream American comic book.

Cassandra’s pre-New 52 adventures included brutal fights against Ra’s al Ghul’s lesser-known daughter Nyssa and her own mother, Lady Shiva. What made Cain so unique in the Bat-family was that her fighting abilities rivaled even that of her own mentor Batman. Her stories were compelling because her growth had little to do with becoming a better fighter (she was already one of the best), but with having a normal life with normal experiences—like her very brief romance with Teen Titans member Conner Kent, AKA Superboy.

However, once her title series ended, writers seemed unsure of what to do with Cass. In a much hated Robin story arc written by Adam Beechen in 2006, Cassandra turned evil and took over the League of Assassins, a complete reversal of the character fans were used to seeing. Realizing how badly they alienated readers, DC eventually blamed her villainous actions on mind-control serum administered to her by the super-assassin Deathstroke. Readers seemed to begrudgingly accept this answer, though by then many writers seemed apprehensive to use her character at all.

More years went by with fans continually asking DC’s editorial staff what happened to their cherished Batgirl. Being one of the few Asian characters on Batman’s team, her absence was even more noticeable to many readers of color. She made brief appearances as a supporting character in team-up books such as 2008’s Batman and the Outsiders, where writer Chuck Dixon infamously had her walk around naked in front of her teammates (by this point Cass was well into adulthood).

In 2009, she was replaced as Batgirl by former Robin Stephanie Brown, which angered some fans even further, but in 2011 she returned briefly in Batman Incorporated as one of Batman’s agents in Hong Kong under a new code-name, the Black Bat. For several more years her character would pop in and out of stories until finally being given yet another new identity in 2016’s Batman & Robin Eternal, this time going by the name Orphan.

While Cassandra Cain’s origins and continuity have fluctuated with each new reboot of DC’s canon, much of it has remained intact. She is the daughter of assassin David Cain, raised to only speak the language of violence and death. She’s one of Earth’s greatest martial artists, easily able to keep pace with the Dark Knight himself. Since DC’s Rebirth launch, Cassandra has been used much more frequently in books, most recently the latest incarnation of Batman and the Outsiders.

Just based off what little is known about Birds of Prey: And the Fantabulous Emancipation of One Harley Quinn, director Cathy Yan has taken many liberties with her film’s characters. Thus far, Cassandra Cain seems like an ordinary, well-spoken girl without any jaw-dropping fighting skills. Though it is still too early to tell what Yan’s plans are for DC’s Daughter of Destruction, many of Cain’s fans seem happy just to see her in a major motion picture.

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