Mild spoilers for tonight's episode of The Flash follow.

In tonight's penultimate episode of Season 2 of The Flash, guest star Katie Cassidy steps in to play a very different role than those she's had before. She's played the lawful Laurel Lance and the crime-fighting Black Canary on The CW's Arrow, but now she'll be taking a trip to Earth-2 in order to bring a very different side of her heroic vigilante to life. In tonight's episode, "Invincible," Cassidy leads a team of metahumans under Zoom's control as they take on Earth-1's defender of Central City himself, The Flash.

But who is Cassidy playing, exactly? None other than the Earth-2 version of Laurel Lance, a metahuman with similar powers to the Black Canary, but who goes by the somewhat darker name of Black Siren. While that character certainly has roots in the history of DC Comics, The Flash is taking some liberties with her and changing things up. We'll clear things up with a little bit of background on Black Siren and how she fits into the broader DC universe.


But before that, check out a preview for tonight's episode along with a clip from EW below, followed by more on Black Siren and lots of images from "Invincible":

Black Siren

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Image via DC Comics

First introduced in August of 1947 in "Flash Comics" #86--though actually featured in a "Johnny Thunder" story within the pages of that issue--Black Canary was created by writer Robert Kanigher and artist Carmine Infantino. This makes her one of DC Comics' earliest super-heroines, offering her the opportunity to join up with such teams as the Justice Society of America, Birds of Prey, and the Justice League of America. She's also partnered up with the Green Arrow quite a bit over the years, both as a crimefighting companion and a romantic interest.

Except Black Canary was originally introduced as a crook. A very particular type of crook--one who only stole from other criminals--but a crook nonetheless. Given the alter ego Dinah Drake, she eventually became a crimefighter instead, partnering up with her beau, Larry Lance, a Gotham City detective. Her criminal background came in handy as she was often found infiltrating gangs in order to bust them up with her expert hand-to-hand combat skills. Eventually she was elevated to a "world-class" martial artist and given the Canary Cry, her sonic scream. Though DC Comics has split the character into a mother/daughter duo and then merged her back into one person over the years, the Black Canary remains a staple of the company.


So, you might be wondering why I spent all that time talking about Black Canary when it's the Black Siren we're supposed to be focusing on here. Here's where it gets a little confusing. The Black Siren is actually Donna Nance, a reference to the Golden Age super-heroine Dinah Drake Lance; the heroic Black Siren is modeled after the Black Canary as well. Nance appeared in the animated series Justice League as the only female member of the Justice Guild of America, itself a nod to the Justice Society of America. The character was a commentary on the sexist nature of the early comic book industry as she was often found in the kitchen, taking on domestic chores, making cookies for the team, and leaving the room whenever the "men needed to talk."

Clearly, Cassidy's performance as Black Siren is going to be quite different and not heroic in the least. It's a fitting name for a character that represents the Earth-2 version of Laurel Lance, a corruption of the character's Earth-1 hero. Personally, I like that they're working the character in, even if it's not in the way we expected. It'll also give Cassidy a chance to have her swan song on The Flash. You can also look out for her appearance in Season 2 of CW Seed's animated series, Vixen.

Take a look at images from tonight's episode, featuring Cassidy in action, below:

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Image via The CW
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Image via The CW

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Image via The CW
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Image via The CW
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Image via The CW
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Image via The CW

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Image via The CW
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Image via The CW
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Image via The CW
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Image via The CW

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Image via The CW
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Image via The CW
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Image via The CW
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Image via The CW
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Image via The CW
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Image via The CW