Summoned back to his old stomping grounds to help investigate a bizarre crime, Capt. Martin Servaz is haunted by a case from his past.

After visiting the prison, Martin realizes the horse may be part of a more sinister scheme. Diane's first session with Hirtmann proves unsettling.

A body found in the woods leads the detectives to re-examine an old case that hits close to home for Irène. Martin follows a clue back to Toulouse.