Jessica Chastain is heading into the darker side of country music in Heartland, the new Netflix thriller that mixes a missing-person mystery with the atmosphere of Nashville’s music scene. Fans of the blend of music, horror, and Southern Gothic storytelling from “ Sinners ” might be drawn to the film, but it takes a different turn, concentrating on a mystery-driven narrative.

Chastain stars as Misty Jones, a former country music star who has been away from the limelight for years. Misty emerges from the shadows to find her niece, an aspiring country singer, missing. Her search takes her to the less glamorous parts of Nashville, where the people she meets may not be telling her the truth.

The film stars Garrett Hedlund, Carter Faith, Ross Lynch, Ben Dickey, Paul Sparks, Skyler Day and Sarah Helbringer.…