LONDON, ENGLAND - DECEMBER 09: Anthony Head attends the Woman's Own Children Of Courage Awards at Westminster Abbey on December 9, 2009 in London, England.

The actor will appear in the final three episodes of season 4.5, which kicks off April 29.

Warehouse 13 is adding a new baddie to the mix.

Buffy the Vampire Slayer alum Anthony Head is heading to Syfy's Warehouse 13 in a major recurring role, The Hollywood Reporter has learned exclusively.

Head will appear in the final three episodes of season 4.5, which kicks off April 29, as the villainous Paracelsus. Character details are being kept under wraps. (Photos of Head with Warehouse 13 co-stars made the rounds on the Internet last fall and Head alluded to his guest spot on Facebook in October.)

The actor, who stars in The CW drama pilot The Selection, joins Polly Walker, Enrico Colantoni, Missi Pyle, Joel Grey, Nora Zehetner, Steve Valentine and Kelly Hu as new additions in coming episodes. Jaime Murray and Kate Mulgrew also return.

Eddie McClintock, Joanne Kelly, Allison Scagliotti, Aaron Ashmore and Saul Rubinek star in Warehouse 13. Jack Kenny is showrunner and executive producer.

The return episode, "The Living and the Dead," picks up moments after the midseason finale with Claudia (Scagliotti) stabbing Artie (Rubinek) -- but not before he infects the team and the world with the Black Orchid artifact's "Sweating Sickness."

Head, known for playing Rupert Giles on The WB's Buffy, is repped by APA and Gordon and French. He next stars in Percy Jackson: Sea of Monsters, Flying Home and Convenience.

Warehouse 13 returns at 10 p.m. April 29 on Syfy.

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