Anna Silk's character in Lost Girl can feel the dark growing within her.

Seriously, isn't there some sort of supernaturally powerful Fae antibiotics that could clear that up in a jiffy?

"You would think by now they would have something, but no," Silk says.

Silk plays lead character Bo in Lost Girl, a Canadian fantasy series that returns for its third season Sunday on Showcase.

Bo is a Succubus who, after her true identity became known to her, found herself caught between the Light Fae and Dark Fae clans. But in season three, the greatest enemy Bo faces might be the one that resides inside her.

"In broad strokes, this season for Bo is about discovery," Silk says. "She really learns, and has to learn, that being Fae is a lot more complicated than choosing Light or Dark.

"She has probably the biggest challenge that she ever has faced, physically, mentally, emotionally. And she really has to come to grips with who she is."

So in other words, the Fae world is not as simple as black or white.

"Exactly, there's more than 50 shades of grey," Silk says.

Wow, good line. Nicely done, Anna.

"I've never actually read the book, but thank you," Silk says with a laugh.

Alongside Silk, Lost Girl's series regulars are Kris Holden-Ried as Dyson, Ksenia Solo as Kenzi, Zoie Palmer as Lauren, Rick Howland as Trick and K.C. Collins as Hale.

Season three of Lost Girl also welcomes Rachel Skarsten to the cast as Tamsin, a sexy new Fae who tends to rock the boat. Emmanuelle Vaugier reprises her role as The Morrigan, leader of the Dark Fae. And making a special guest appearance is the legendary Linda Hamilton as Acacia, a ruthless assassin.

A key element to the continued success of a genre show such as Lost Girl is that the main cast has to remain engaged and intrigued, and also has to be seen by the audience to be engaged and intrigued. If that interest level drops at all, hardcore fans can sniff it out.

"We are -- well, I obviously can't speak for everyone, but it feels like we all are (engaged and intrigued)," Silk says. "I definitely have not been bored yet, which is really, really nice. But I think the central draw is the characters on the show and the relationships that exist between them.

"When we started, the idea of playing Fae, or playing a Succubus, it sounds daunting. But if you break it down and realize that you can't really play that, then you play the human side, and you use your imagination to build in or fill in that gap of what makes you supernatural.

"You just play the reality of the situation. The scenarios are fantastical and there are creatures and spells and things happening all the time that are just completely out of our own reality. But it's not out of their reality, you know?"

Now if only Lost Girl's "reality" included some fancy Fae drugs to deal with that nasty inner Dark problem.

"Not yet," Silk says.

Hey, when they do exist, they might be covered by Canadian healthcare.

bill.harris@sunmedia.ca

@billharris_tv