'Revenge' has mother of all plot twists

"Revenge" -- the Hamptons-set series that begins its second season Sunday at 9 p.m. on ABC/7 -- hooked an enthusiastic fan base in season 1 with its taut storytelling and stunning surprises. Wait -- that wasn't Daniel Grayson who was murdered on the beach? OMG! Did Victoria just get blown up?

And every now and then, the show's writers came up with a stunning revelation for the lead character, Emily Thorne, that knocked even the show's star, Emily VanCamp, for a loop. In this case, it was discovering that Emily's mother is alive.

"Going into season 2, this is proving to be Emily's greatest challenge yet," she says. "You see her unraveling a little bit. Emily's determination to find her mother becomes unhealthy, obsessive and really dangerous."

That adds another layer to the staggeringly complex role VanCamp has been entrusted with: Emily Thorne, born Amanda Clarke, who has returned to her old hometown to wreak vengeance on the people who conspired to destroy her beloved and innocent father, David.

"I have so many journals and binders filled with notes just trying to keep track of different things, and my scripts have scribbles all over them," VanCamp says. "This is a very difficult show to keep up with. I'm playing scenes where I have to mask all this internal stuff that's going on."

This season, it gets even more complicated, as Emily meets the mother (played by new cast member Jennifer Jason Leigh) whom she hasn't seen since she was 4 or 5.

"I absolutely love the exploration of that mother-daughter relationship," VanCamp says. "It's almost as if Emily is looking into a mirror when we see that relationship, and she starts to wonder whether she is developing the same mental disorders as her mother. It's just a very different place to see Emily in, because she normally isn't nearly this vulnerable."

Her vulnerability is further enhanced by the introduction of a new character played by British actor Barry Sloane.

"He's a mysterious romantic interest from Emily's past when she was in Japan," series creator and executive producer Mike Kelley explains. "The character is called Aiden, and I think the audience is going to fall in love with him. He's sort of a Daniel Craig-ish character."