Laurel Lance is back! Sort of. Though her character died in Season 4, longtime "Arrow" star Katie Cassidy will return, but with a twist: she will play Black Siren, Earth-2's evil version of Laurel, as a series regular in Season 6. Additionally, Black Siren will feature in the last two episodes of Season 5.

"One of the things that most excites us about 'Arrow' is that we go where the story takes us. Last year, the story took us to the tragic death of Laurel Lance. This year, our midseason finale reintroduced us to Laurel’s doppelgänger, Black Siren," explained executive producer Marc Guggenheim in a statement. "We were so taken by Katie’s fearless interpretation of this character that we knew her story was not yet finished. We couldn’t be more thrilled to welcome Katie back to 'Arrow' as Black Siren, though as her appearances on 'Arrow' and 'DC’s Legends of Tomorrow' this season show, she never really left the family."

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Back in July 2016, executive producer Wendy Mericle announced that Cassidy had struck a deal with The CW that makes her a series regular across all of the network’s superhero shows, including "The Flash" and "Legends of Tomorrow." Cassidy subsequently showed up in "Arrow" and "Legends of Tomorrow" for a few episodes, but nothing more seemed to come of this agreement. However, it seems the network will embrace this deal moving into "Arrow" Season 6.

Cassidy played Oliver Queen's love interest Laurel Lance over the first four seasons of “Arrow.” In Season 3, she became Black Canary to honor her sister Sara, a former Black Canary who was murdered by Malcolm Merlyn. In Season 4, Laurel herself was killed by HIVE leader Damien Darhk.

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Nevertheless, that wasn't the end of Laurel. Her Earth-2 doppelganger Black Siren debuted in a Season 2 episode of "The Flash." Unlike Earth-1's Laurel, Black Siren is a metahuman with a super sonic scream and -- instead of becoming a hero -- she used her powers for evil, aligning with the evil speedster Zoom. When Zoom fell, she was imprisoned by Team Flash, only to be freed by Prometheus in a bid to torture Oliver. Since then, she has been imprisoned once more.

At this time, it's unclear if Black Siren will be a protagonist or antagonist in Season 6. Additionally, Team Arrow has found a new Black Canary in Dinah Drake, so it is also unclear how Black Siren's return will impact her role on the team.

Starring Stephen Amell as the Emerald Archer, “Arrow” airs Wednesdays at 8 pm ET/PT on The CW. The series also stars Emily Bett Rickards, David Ramsey, John Barrowman, Willa Holland and more.