Emily Bergl Emily Bergl

Emily Bergl has landed a guest-starring role on Elementary, TVGuide.com has learned exclusively.

The Shameless star, who was recently promoted to series regular on the Showtime dramedy, will play Marion West, an alternative tattoo artist who becomes a suspect in her ex-husband's murder.  

"Sherlock [Jonny Lee Miller] and Joan [Lucy Liu] are looking into the case and start to think it's not really what it appears to be," executive producer Rob Doherty tells TVGuide.com. "It appeared to be a home invasion gone terribly awry, but they're beginning to suspect that the scene was set to look that way. So they certainly have questions for [Marion]."

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However, Sherlock will make a startling discovery through the investigation. "As Sherlock and Joan start to get a better sense of Marion, what they find is that her husband had a secret connection to Sherlock and Mycroft [Rhys Ifans]. They realize that her husband is someone who once upon a time was tasked with keeping an eye on Sherlock Holmes."

Bergl, whose credits also include Desperate Housewives and Southland, will appear in the drama's May 8th episode.

Elementary airs Thursdays at 10/9c on CBS.

(Full disclosure: TVGuide.com is owned by CBS.)