Dylan Walsh is set to follow in the Castle-based footprints of Dana Delany, Adrian Pasdar and Jennifer Beals.
The former Nip/Tuck star, who will also be seen later this year on Revenge, is the latest big name to sign on for the Castle two-part episode that takes place each year in February.
According to TV Line, Walsh will portray FBI Agent Harris, an investigator who teams with Rick and Kate to get to the bottom of a kidnapping plot that involves the daughter of a Middle Eastern businessman.
Walsh has recently appeared on CSI and Drop Dead Diva. He also plays a role on Unforgettable, which returns to CBS this summer.