Robert Sean Leonard and Gloria Reuben have both signed on for Falling Skies Season 3.
The long-running House star will portray Dr. Roger Kadar on the TNT drama next summer, a scientist who runs Charleston’s power grid and lives underground... with his pet rats.
Known as "The Rat King" to other residents, Leonard's character will appear on five episodes.
Reuben, meanwhile, will reunite her ex-ER costar as Marina Perlata, a fellow human resistance leader who will work closely with Noah Wyle’s Tom Mason.
Deadline first reported this Falling Skies casting news.