Boardwalk Empire alum Jack Huston and Maximiliano Hernandez (Sicario) have joined the Season 2 cast of AT&T Audience Network’s breakout series Mr. Mercedes. Production begins next month in Charleston, South Carolina on the Sonar Entertainment-produced Stephen King adaptation for premiere this summer on DirecTV, AT&T U-verse and DirecTV Now.

The second season will be based on King’s best-selling Bill Hodges Trilogy, which includes, Mr. Mercedes, Finders Keepers and End of Watch.

Season 1 followed a demented killer Brady Hartsfield (Harry Treadaway) who taunts a retired police detective Bill Hodges (Brendan Gleeson) with a series of lurid letters and emails, forcing the ex-cop to undertake a private, and potentially felonious, crusade to bring the killer to justice before he is able to strike again.

Huston will play Brady Hartsfield’s doctor Dr. Felix Babineau and Hernandez will portray Assistant DA Antonio Montez.

In addition to Treadaway and Gleeson, Huston and Hernandez join returning cast Jharrel Jerome as Jerome Robinson, Scott Lawrence as Detective Peter Dixon, Breeda Wool as Lou Linklatter,, Justine Lupe as Holly Gibney and Holland Taylor as Ida Silver.

David E. Kelley (Big Little Lies, Ally McBeal) and Dennis Lehane (Mystic River, The Drop, Live by Night) will be leading the season 2 writers room. Jack Bender (Game of Thrones, Lost, Under the Dome) will return to direct 8 of 10 episodes. King, Kelley, Bender and Marty Bowen of Temple Hill Entertainment will continue to serve as executive producers, along with Lehane.