 Lundy devotes 15 years of his career to hunting down the "Trinity Killer", tracking him and seeing him as the most elusive serial killer he has ever encountered, but cannot convince any of his colleagues that Trinity even exists.During the hunt for the Bay Harbor Butcher, Lundy became dangerously close to finding out Dexter is the Butcher he is seeking, and at the same time becomes involved in a relationship with Debra, helping her get over her left-over chaotic emotions from her time as the prisoner of the Ice Truck Killer.In the end, Dexter outmaneuvers and frames Doakes as the Butcher, causing Lundy to lead the entire police force in a full-scale manhunt to find Doakes.