Jeremy Irons and Elizabeth Mitchell

While Lost's Juliet is dead and V's Erica Evans is on the brink of humanity's extinction, Elizabeth Mitchell has a new role to play: suspected rapist.

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The actress will appear in Wednesday's episode of Law & Order: Special Victims Unit as June Frye, a piano teacher accused of killing a little girl after raping her with a rolling pin — a role Mitchell says she wasn't attracted to.

"Neal [Baer] asked me to do it," she says of SVU's executive producer, whom she worked with on ER. "He said, 'You can come work with Jeremy Irons, and we're writing a really messed-up role. Want to come do it?' and I said, 'Sure!' I'm pretty clear about what I will and won't do, so that was taken into consideration. As a whole, we were pretty honest and pretty respectful. I'm hoping to shed some light on a situation that we don't talk about very often."

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Unlike some of her past characters, who were often strong but sometimes faulty, June "is so damaged and so violated," Mitchell says. "The episode is really, really, really dark, but there are twists to the story and it isn't all what it seems. We don't know if she did it or not. I think you'll be intrigued by it, if you can stomach watching it. It is pretty hardcore."

Check out this first look at Mitchell on Law & Order: Special Victims Unit: