Orphan Black's Sarah is about to get some bad news. She has an infection, and it's defiantly not one your average doctor is familiar with.

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The season 3 finale left us with the horrifying image of Dr. Nealon (Tom McCamus) seeming to regurgitate a worm to feed to Delphine (Evelyne Brochu), and that squirmy little bugger will come back into the picture sooner rather than later.

In an interesting twist, Zap2It has revealed that Mrs. S. (Maria Doyle Kennedy) will discover a similar creepy crawly burrowing into Sarah's (Tatiana Maslany) cheek. The sneak peek was only shown to TCA attendees, but you can get a rather terrifying look at the scene courtesy of the BBC America Tumblr. Click here if you're not in the least bit squeamish.

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Little is known about Dr. Nealon's worm(s), but it's safe to assume that answers will be forthcoming early in season 4.

"It's been part of our unfolding science, and unfolding bio-horror aspect," series creator Graeme Mason teased, according to The Hollywood Reporter. "And bio-tech. Those elements are something we're really interested in. Like [the finale] said, "The science is far beyond what you could imagine."

Find out more when Orphan Black returns to BBC America in April.