Shannen Doherty

After a 29-year career on the screen — not to mention the Dancing with the Stars floor — Shannen Doherty has a new goal: to go viral.

"The web's ... definitely an area I've been looking to get into," Doherty tells TVGuide.com. "I think it's an interesting way to view content. It doesn't cost a lot of money and you don't have to go through [red tape] to get your projects out there. I think before there was a stigma about doing things online and people were maybe [hesitant] about it, but it's really come into its own the past few years. It's definitely the future."

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Doherty's first foray into the medium is on FEARnet.com's Mari Kari, which premieres Thursday. Modeled after Japanese anime, the tongue-in-cheek eight-episode horror series — each episode lasts one to two minutes — revolves around a set of school-age twins, Mari and Kari, who are about as polar opposite as you can get. For one thing, Kari is dead and Mari is very much alive.

Doherty, 39, lends her vocal skills to both girls: the naïve and perky Mari, and the dark and sinister Kari.

"It's funny because I originally thought that Mari was going to be the harder voice to do because she is so super bubbly and kind of annoying. Everything's like [high-pitched] 'Oh my God!'" Doherty says. "I thought, 'Ugh! How am I going to do this?' ... She ended up being much easier than Kari to be honest. Although Kari is my voice, she's not my voice because it's even deeper and raspier and more deadpanned. There are not a lot of voice inflections or emotional inflections at all. I found her to be a little bit more difficult and a bit of a bummer, actually, especially after doing Mari."

Doherty, whose last voiceover work was in 1982's The Secret of NIMH, recorded all the dialogue in a day — another plus for the web medium.

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"There's no hair and makeup time!" she says. "I'm notorious for [getting] annoyed and impatient in a makeup chair. ... It was amazing going in and working for a day, doing eight episodes in a day, and having no hair and makeup time. I went in jeans and T-shirt. I was thrilled about it!"

Less thrilling is the grotesque wrath revenge-filled Kari unleashes on Mari's classmates when they taunt and torment her. So is she killing to protect her gullible sister?

"I think so — and because she's not a nice person, dead or alive," says the Beverly Hills, 90210 alum, whose career began with a couple episodes of Father Murphy in 1981. "She hinges toward violence for sure. They're the antithesis of each other, but they hang onto each other. I don't think we find out how Kari died, but they're both in denial that she's dead. Mari loves her sister and Kari's not crossing over and is not at peace. ... I don't think it's like Lost though!"

The series wraps with a cliffhanger at the prom ("What Kari does is pretty insane") and Doherty hopes to reprise her double-duty voiceover.

"It depends on how many people respond to it and if they ask me back," she says. "They're so well-written and hysterical. I see life in it."