'Arrow' Reveals New Details About Black Siren's Backstory in "Past Sins"

Arrow took a deep dive into two of its characters tonight, and we found out a lot more about one character's origins in the process.

Spoilers for tonight's episode of Arrow, "Past Sins", below!

The episode began with a television interview of Laurel Lance (Katie Cassidy) and Oliver Queen (Stephen Amell), which ended up having an interesting ripple effect on the rest of the episode. In a bar soon after, Laurel was approached by a man named Brett Collins, something that caught Laurel off guard.

As Laurel later explained to Felicity Smoak (Emily Bett Rickards), the Collins of Earth-2 was the man who caused the car accident that killed her father when she was younger. Laurel still was overwhelmed with guilt about her father's passing, which she felt that she'd caused by getting into a fight with him shortly before the crash. When Laurel got her Canary Cry, she immediately used it to hunt down Earth-2's Collins and kill him, which made her wonder which version of the man was stalking her now.

In the episode's end, Laurel and Felicity met with Dinah (Juliana Harkavy), who reassured that Collins would be arrested and held in custody for the rap sheet he had on Earth-1 -- and that Earth-2's version of Collins had died five years before.

For Laurel fans, this new bit of backstory was a long time coming, as a lot was (and still is) unknown about how she got on the path to becoming Black Siren. And with Laurel set to take the spotlight in a Birds of Prey-esque episode later this season, fans will have to see if all of this snowballs into a bonafide redemption for her.

"I think, the team, she could definitely be of service to, if they trust her." Cassidy told ComicBook.com last year. "I think that'd be a really interesting situation, if the writers decide to go with that route. But I think her having the ability to be this chameleon, and change personalities, and go undercover and in disguise and be this female Jason Bourne is great."

"I think there's room for redemption for her character." Cassidy continued. "And I think, what I believe is that if they do reveal more of her backstory, and sort of tell her story actually, there'll be a lot more of an understanding of why she acts the way that she does."

You can check out the synopsis for "Past Sins" below!

"DAVID RAMSEY DIRECTS HIS FIRST EPISODE OF ARROW

The past comes back to haunt both Oliver (Stephen Amell) and Laurel (Katie Cassidy). Curtis (Echo Kellum) is upset when he discovers that Diggle (David Ramsey) and Lyla (guest star Audrey Marie Anderson) have restarted The Ghost Initiative with Diaz (guest star Kirk Acevedo), China White (guest star Kelly Hu), Kane Wolfman (guest star Liam Hall) and Carrie Cutter (guest star Amy Gumenick).

David Ramsey directed the episode written by Onalee Hunter Hughes & Tonya Kong."

Arrow airs Mondays at 8/7c on The CW.