Season 1:
Rustin 'Rust' Cohle is a Louisiana State homicide detective who transferred out of Texas law enforcement. A talented but troubled man, he holds a negative view of society which sometimes puts him at odds with his partner, Martin Hart, and the rest of the force. Rust is also prone to auditory and visual hallucinations resulting from substance-abuse during his days as an undercover narcotics officer. He carries an unusually large ledger which he uses to keep notes and sketches of crime scenes, earning him the nickname 'the Tax Man' from his colleagues.

In 1995 Rust and his partner are called to the scene of a gruesome, ritualistic killing of a young woman who was posed, symbols carved into her skin, and adorned with a crown of deer antlers on her head. Fast forward 17 years to 2012 where Cohle and Hart are being grilled by another pair of detectives, Thomas Papania and Maynard Gilbough, who are investigating a case that bears striking similarities to the 1995 case. In between is a glimple of 2002, when Cohle and Hart struggled to deal with their inner demons in separate, but equally destructive ways.