Howard Charles (The Musketeers) and Elizabeth Laidlaw (Boss) have signed on as series regulars opposite Emayatzy Corinealdi, Noel Fisher, Michael Patrick Thornton and Aliyah Royale in CBSRed Line, a racially charged hourlong drama executive produced by Ava DuVernay and Greg Berlanti.

Written by Caitlin Parrish and Erica Weiss and directed by Victoria Mahoney, Red Line explores what happens after a white cop in Chicago mistakenly shoots and kills a black doctor. We follow three different families that all have connections with the case as the story is told from each perspective.

Charles will play Ethan, Tia’s (Corinealdi) warm, kind husband who works as a train operator on Chicago’s Red Line. While he supports his wife’s political career, he cautions about reconnecting with her biological daughter.

Laidlaw will portray Vic, a hard-working mother of two children and devoted police partner of Pete Evans (Fisher), who shot an African-American doctor. Her unconditional loyalty to her partner led her to take a questionable action.

Charles, who played Porthos in BBC America’s The Musketeers, next will be seen in Amazon’s eight-episode thriller The Widow opposite Kate Beckinsale. He’s repped by Paradigm, Grandview and United Agents in the UK.

Laidlaw recently recurred on Chicago P.D. She’s repped by Stewart Talent.