'Secret Circle' Star Shelley Hennig Talks Secret Sibling, Tonight's 'Traitor'

Shelley Hennigby Ryan J. Downey

Last week, "The Secret Circle" unwrapped one of the biggest surprises of the season: the identity of the other Blackwell in the crew.

Cassie Blake's half-sister is none other than her one-time romantic rival, Diana. Shelley Hennig couldn't be more pleased about the revelation surrounding her character. Speaking to Hollywood Crush by phone, she also revealed how pleased she is with our longstanding use of the phrase "The Secret Sibling" in our blog.

"I like how you worded that, 'The Secret Sibling,'" she said with a chuckle. "That's amazing.

"I found out [about the revelation] a few days before we started shooting," she explained. "It wasn't something that had been circulating with the cast. I was shocked but I also didn't believe it. I wasn't convinced, but I was super-excited. It wasn't until we were actually shooting it that I was like, 'All right, it's for real!' Because they'll change things. We'll get a script and then it'll be completely different the next day. I was excited to have that happen and also to see [where it's going to go]."

The news wasn't a total shock to her, however, at least not on an intuitive level. "I was thinking it would make sense as to why Diana went to Cassie first after she and Adam broke up. There's a connection there. There's something undeniable between Cassie and Diana that we've explored since episode one. For me, it made sense."

What will Diana's immediate reaction be when things pick back up in tonight's new episode, "Traitor"? "Diana wants to find out if it's even true. She doesn't totally believe Cassie. She goes to Charles to get the answers. There's a great scene between Charles and Diana where she confronts him and she finds out more and whether Charles knew all along. There's some surprises on both ends. Charles tells her John Blackwell can't be trusted, which is why Diana has to tell the Circle what's going on. They want to use John Blackwell to save themselves, but Diana has new information. She wants to tread lightly, because if she comes in and tells them about John Blackwell's intentions, nobody will follow her. She has to show them slowly that what his intentions are are not what the Circle wants."

We've spent the entire series thinking that Cassie and Adam are fated to be together, whether that's a blessing or a curse, thanks to their bloodlines. Now that we know Diana shares a bloodline with Cassie, could that mean she is in fact fated to be with Adam herself? Not necessarily, Shelley pointed out. "I don't know how that works. I thought about that. But when Adam's father would talk about that, he would mean Cassie Blake—Blake, her mom's side. But who knows? I mean, I think Adam and Diana have their thing as well. So, who knows! I did think about it, like, 'Ooh, that's interesting!' Very incestuous here. I guess we'll see!"

Faye spent most of "Crystal" hoping that John Blackwell was her father, more or less coveting that Secret Sibling role. Fans have really taken an interest in the "Fayana" friendship both onscreen and off. So what will last week's revelation mean for those two in tonight's new episode, "Traitor," and beyond?

"That's a good question. I think Faye is going to be jealous that Diana is a Blackwell because all Faye wants is power. Who knows? I'm thinking season two here, but, maybe she'll try to convince Diana to tap into that dark magic so Faye can try to get a piece of it. But as of now, I think Faye is just jealous."

When "The Secret Circle" began, Diana was something of the de facto leader and moral compass of the group. In last week's episode, "Crystal," she started wanting a life outside of the Circle (thanks in no small part to a certain Australian boatman), just before Cassie said those three little words: "You're my sister."

"Diana was the one that convinced Cassie to be a part of [the Circle] and now Diana doesn't want to be. The role has reversed for her," Shelley said.

"It's about Diana trying to be normal but the obstacle is the life and death situations with the Circle and magic. Diana is just blindsided by Grant and the fact that he's just a normal—and not to mention, very good-looking—guy with an accent who has just kind of shown up in Chance Harbor. He's a great guy and maybe someone that she wants to pursue a relationship with. But what gets in the way, in the season finale and in 'Prom,' are the life and death situations of finding the crystals and protecting themselves. And also John Blackwell's intentions, which we find out are not good."

"Traitor" and "Prom," the next two episodes, are leading up to the climactic events of the season one finale, "Family," which is scheduled to air May 10. Tonight's episode will see Diana going to Charles, who she thought was her father, for answers. A life and death situation involving one of the crystals during prom will mess with Diana's love life once again. By the time we reach "Family," things will come to a head with the witch hunters as Blackwell pushes Cassie and Diana to get darker.

With the Secret Sibling revealed, a couple of big mysteries remain: What's the complete truth behind the events of 16 years ago, and when will people discover that Charles killed Cassie's mom back in episode one? "In the 'Prom' episode, Diana and Cassie team up to locate the crystals that Adam has uncloaked in the high school. With that, they find out more information about what happened 16 years ago to our parents and what John Blackwell's position in that was," Shelley revealed.

And as for Charles? "Charles starts to lose it. He starts to unravel. Diana is not sure if it's because he can't deal with the fact that I'm not his daughter or if there are other things going on. We'll definitely explore both of those."

What do you think of Diana being the Secret Sibling? How do you want to see that play out in the last few episodes of the season? Weigh in in the comments below and on Twitter!