Felicia Day

The Dungeon Master has orchestrated a fun adventure for Supernatural. Geek worlds collide in an upcoming episode when someone from the Whedonverse gets mixed up with the Winchester brothers.

Executive producer Sera Gamble tells TVGuide.com exclusively that Felicia Day will guest-star on the April 27 episode titled "The Girl With the Dungeons and Dragons Tattoo." "We were so stoked that she agreed to do the episode because we're all fan girls and boys here," Gamble says.

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The title is a reference to the bestselling Steig Larsson crime novel The Girl With the Dragon Tattoo and the acclaimed big-screen adaptation of the same name. Like Larsson's protagonist, Day will portray a young woman who's handy with a computer. Day has serious geek cred, not only appearing in numerous Joss Whedon projects such as Buffy the Vampire Slayer, Dr. Horrible's Sing-Along Blog and Dollhouse, but also created, wrote and stars in the original web series The Guild, about a guild of online gamers.

"Felicia plays a girl named Charlie who is sort of a lowly tech working in one of Dick Roman's companies," says Gamble. "She's an amateur computer hacker and unwittingly gets wrapped up in Sam and Dean's problems. It's a classic story of an everyday girl who does not want to be in a whistleblower position."

Dean (Jensen Ackles) has been obsessed this season with getting closer to Dick Roman (James Patrick Stewart), the billionaire who was taken over by the leader of the Leviathans, and Charlie could be the key to getting Dean closer to the corporate giant.

But before that happens, Supernatural returns with an all-new episode Friday (9/8c) that challenges Dean's will power.

"Our boys pick up a crazy case in which a ballerina dances her feet off; her shoes are a cursed object," says Gamble. "There's a lot of pretty famous fairy tales in Western folklore, like 'The Red Shoes,' that are similar. In the case of this cursed object, if you touch the shoes, you become so enamored of them, you just want to put them on. They kind of follow you around until you do, and we see this happen to a couple different people.

"In the course of wrestling them off somebody, Dean does touch them," she continues. "So he starts to get the urge to put them on. It becomes a high-stakes race as to where this cursed object came from, and are there curse boxes they can shove it back into quickly before Dean becomes the next victim."

Will Dean prevail? Or will he also pull on a tutu?

"I don't know if Jensen would want to put one on, as comical as it would seem," says Gamble.

Supernatural airs Fridays at 9/8c on The CW.

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