Rhona Mitra has boarded the independent thriller The Boy in the Box for A2 Entertainment Group and Code Entertainment, according to The Hollywood Reporter.
She joins Josh Lucas and Jon Hamm in the film about a small-town police chief (Hamm) determined to discover the truth behind the mummified remains of a boy who was murdered a half-century earlier.
Anders Anderson is directing from a screenplay by Glenn Taranto.
Mitra plays the police chief's wife, who is trying to move on after the disappearance of their own son eight years earlier. Lucas plays the father of the murdered boy.