After the grim discovery of a missing man's body in the trunk of his car, 15 Division must try to find out what happened to Brian Gowdy - a high school teacher with no apparent enemies. While trying to track down their prime suspect, Andy and Sam go on the road to interview a list of prison inmates, leading them to someone with a surprising connection to Sam. Meanwhile, back at 15 Division, Traci leads the investigation and realizes they may have the wrong suspect.