EXCLUSIVE: Toni Collette, Homeland‘s Tracy Letts and Sam Trammell have joined the cast of Daniel Ragussis’ Imperium, the Lionsgate Premiere thriller that stars Daniel Radcliffe. Radcliffe plays an FBI agent who goes undercover and infiltrates a white supremacist group to expose a terrorist plot to create a dirty bomb. While investigating the group, he is faced with the challenges of maintaining his principles while trying not to blow his cover.

Sam TrammellCollettte will play Angela Zampino, a battle-hardened FBI agent. Letts will take on the role of Dallas Wolf, a modern-day leader of the white supremacy movement. Trammell will play Jerry Conrad, an overtly average father in suburbia who, in actuality, is the local Ayran Youth recruiter.

The pic, which marks Ragussis’ feature directorial debut, is based on the experiences of Michael German, a former FBI undercover agent who spent years inside U.S.-based neo-Nazi and militia groups. Ragussis and German co-wrote the script, and filming is set to begin this week in Hopewell, VA.

Atomic Features and Tycor International Film Company’s Ty Walker, Dennis Lee and Simon Taufique are producing with Ragussis. Andrew Mann, Jeff Elliott, Chad Moore, Barry Brooker, and Stan Wertlieb along with Eric Gold and Warren Goz of Sculptor Media are executive producing. Green-Light International is handling foreign sales and brokered the Lionsgate deal. 

Collettte, the Oscar nominee repped by CAA and Finley Management, is next up in Legendary’s Krampus later this year. Letts, also a Pulitzer- and Tony-winning playwright, will next appear in The Big Short, also to be released in December. He is repped by Innovative Artists. Trammell, also with Innovative, previously starred in teen melodrama The Fault In Our Stars.