Jane Seymour on her 'Castle' guest spot: 'I've played a lot of very evil people in my time.'

Jane Seymour, noble Dr. Quinn, medicine woman. She could never harm a thing. Or could she?

You won’t be so sure during tonight’s meta-tastic episode of Castle‘s “One Life to Lose,” which follows Castle and Beckett as they solve a murder that has taken place on the set of a soap opera called Temptation Lane. Seymour plays Gloria, the suspicious mother of the victim who finds herself (in true soap fashion) among a large group of suspects entangled in the mystery.

“As far as we can tell, she really is not necessarily all we imagine her to be. There’s more to Gloria than meets the eye,” she says. And that “more” is nothing good, but for Seymour, who will next be seen in the indie flick Lake Effect, that’s the best part.

“People always think that because of Dr. Quinn that I just play nice family stuff. But the truth of the matter is that East of Eden was a very successful thing for me in the past,” she says, referring to her manipulative character on the miniseries, Cathy Ames. “I’ve played a lot of very evil people in my time.” And after tonight, we’ll all be reminded that she does it rather well, too.