In Season 4, Raylan will start to pick at the thread of a cold case over 30 years in the making, unraveling a riddle that echoes all the way back to his boyhood and his criminal father's bad dealings. Meanwhile Boyd Crowder finds his grip on Harlan loosening due to a Pentecostal preacher with a penchant for theatrics and a knack for manipulation to rival his own.

Follows a single sprawling drug and murder investigation in Baltimore. Told from the point of view of both the police and their targets, where easy distinctions between good and evil are challenged at every turn.

"With the fall of the Barksdale empire, and the ascent of a new young drug king in Baltimore, McNulty, Bunk and the rest of the detail continue to "follow the money" up the political ladder amidst a hotly contested mayoral campaign. Prez witnesses first-hand the role of inner-city education in the formation of youth as four students, Michael, Namond, Randy and Dukie, face dangerous decisions and adolescent angst in a city rife with the temptations...