Arrow Season 3 Spoilers: What Causes Sin to Return?

The CW's Arrow is back with all new Season 3 episodes, and fans learned a while back that Bex Taylor-Klaus would return as Sin, Sara's protégé, in an upcoming episode. But what brings Sin back into the fold?

The "Spoiler Room" column at EW.com has some information.

"Do you have any Arrow scoop on Sin's return? - Chris
You can thank Brick's plan to take over the Glades for her return. 'We have to go back to the Glades to check things out and check on some people and survey the area,' Colton Haynes tells me. 'I finally get to see Sin again and might recruit her to come help us along the way.' Speaking of returning faces, when Ra's al Ghul pops back up in Starling City, the team may find an ally in Nyssa... until she finds out who really killed Sara. 'Thea really has to watch her back,' Haynes says. 'I feel back because it's not her fault. It's Malcolm's fault.'"

In related news, the official description for Episode 13, entitled "Canaries," has been released.

"VERTIGO (GUEST STAR PETER STORMARE) RETURNS AND PITS CANARY AGAINST BLACK CANARY - Oliver (Stephen Amell) is thrown by the changes within Team Arrow. He's used to calling the shots but sees that the team has evolved in his absence and tensions quickly escalate in the lair. Oliver is furious that Laurel (Katie Cassidy) has been going out as the Black Canary and tells her to stop risking her life, but when Vertigo (guest star Peter Stormare) hits the streets again, Laurel goes against Oliver's wishes and tracks down Vertigo who hits her with a full dose of the drug. Laurel's biggest fears revolve around her sister Sara (guest star Caity Lotz) so the Vertigo causes her to hallucinate an epic fight between Canary and Black Canary. Meanwhile, Chase (guest star Austin Butler) surprises Thea (Willa Holland), and Roy (Colton Haynes) warns Thea to stay away from Malcolm (John Barrowman). Michael Schultz directed the episode written by Jake Coburn & Emilia Ortega Aldrich."

What do you think will happen when Sin returns? Let us know in the comments section.