The Mikaelsons are in for a lot of trouble on The Originals now that the character of Dahlia has officially been cast.

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On Monday The Hollywood Reporter announced that Farscape star Claudia Black has stepped into the role of Esther's (Sonja Sohn) fierce and unforgiving sister. Back when the Mikaelsons were still mortal, Dahlia helped Esther to have children in exchange for each first-born child of every generation. She stole Freya (Riley Voelkel) away before Klaus (Joseph Morgan) was even born and now she's preparing to return for Klaus and Hayley's (Phoebe Tonkin) baby daughter, Hope.

"If Freya is still alive, that must mean Dahlia is still out there," teased executive producer Michael Narducci. "And what's the nature of their relationship? All of that is the stuff we want to play going forward."

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Freya has already claimed that she fled Dahlia years ago, though it is uncertain exactly where the long-lost Mikaelson's loyalties truly lie. Does she really wish to stop Dahlia and save Hope? Or is her return a ploy to draw Dahlia closer to Klaus' daughter? Klaus, Elijah (Daniel Gillies), and Rebekah (Maisie Richardson-Sellers) will spend a fair amount of time this season trying to figure that out.

Black will make her debut as Dahlia in episode 16, which means that the stakes will get pretty high very soon.

The Originals will return on The CW for the remainder of its second season on Monday, March 9 at 8 p.m. ET/PT.