Buffy's Back: Watch a Trailer for the New Sarah Michelle Gellar CW Series 'Ringer'

The new Sarah Michelle Gellar series "Ringer" has sort of a convoluted set-up, but we shouldn't be too surprised. It'd probably take quite a story (or quite a cash flow problem) to get Gellar back on television.

On the show, Gellar gets the unique challenge of playing twins.

"Bringing to life two characters and making them different, but at the same time interesting, and [showing] the similarities is definitely a challenge I've never done," Gellar told Entertainment Weekly.

Her main character, Bridget, is a recovering drug addict who's life is on the mend when she witnesses a mob killing.

Even though her FBI protector, Agent Victor Machado (Nestor Carbonell of "Lost" fame), assures her that she'll be safe, she can't accept it and flees to New York to reunite with her twin sister, Siobhan. After she goes missing, Bridget realizes this is the answer she's been looking for and decides to pose as Siobhan.

But there's that thing about best laid plans and all that, and it turns out that Siobhan's life isn't as fairy-tale perfect as it seems. Sure she's married to a character played by Ioan Gruffudd (formerly Mr. Fantastic of "The Fantastic Four"), but it turns out she has people trying to kill her as well. And if people are trying to kill Siobhan, obviously they weren't the cause of her disappearance, so either Siobhan has more enemies than Bridget thought, or Siobhan just bolted.

Whatever the case, Gellar promises the show is full of surprises. "This is the person who, in the middle of 'The Sixth Sense' yelled out, 'Oh my God! He's dead!'" Gellar said, referring to herself. "Usually I see it coming, and I didn't see [the plot twists in 'Ringer'] coming."

Check out a the CW promo for "Ringer":