FX's The Strain continues to bulk up on its cast.

Showrunner Carlton Cuse took to Twitter to announce that the drama pilot from Guillermo del Toro has enlisted Lord of the Rings alum Sean Astin.

Based on del Toro and Chuck Hogan's book trilogy first published in 2009, the story centers on a vampire virus that infects New York and the CDC doctor, Ephraim "Eph" Goodweather (House of Cards' Corey Stoll), who investigates the case. Goodweather is the head of the CDC's Canary Team in New York who is called upon to investigate a viral outbreak connected to an evil strain of vampirism. As the strain spreads, Eph will lead a team of New Yorkers as it wages a war and defends humanity.

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Astin, sources tell The Hollywood Reporter, will play Jim Kent. The character is a savvy and trustworthy guy who is an open political operative of the Canary Group and best friends with Goodweather and Nora (Alias' Mia Maestro). He unknowingly betrays their friendship when he is coerced into releasing a cabinet out of quarantine that contains a potentially deadly virus. When asked why, Jim confesses he was embezzling CDC funds to help pay for his and his girlfriend's IVF treatments.

Del Toro and Hogan, who co-penned the three-book series, will co-write the pilot, with Bates Motel's Cuse onboard as showrunner. Del Toro will direct the pilot, which hails from FX Productions.

FX Networks president and GM John Landgraf told reporters in March that The Strain, which is prepping to film its pilot, already had assembled a writing staff and picked up additional scripts, a strong sign the pilot will earn a series order.

Astin, repped by Innovative Artists, Luber Roklin Entertainment and Bloom Hergott, joins a cast that also includes John Hurt, Jonathan Hyde, Kevin Durand and more. His credits also include CBS' failed pilot The Surgeon General and a voice role in Nick's Teenage Mutant Ninja Turtles.

E-mail: Lesley.Goldberg@THR.com

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