The disappearance of a young Arkansas boy and his sister in 1980 triggers vivid memories and enduring questions for retired detective Wayne Hays who worked the case 35 years ago with his then-partner Roland West.

Hays looks back at the aftermath of the 1980 Purcell case, including possible evidence left behind at an outdoor hangout for local kids. As attention focuses on two conspicuous suspects, the parents of the missing kids receive a cryptic note from an anonymous source.

Hays recalls his early romance with Amelia, as well as some cracks in their relationship that surfaced after they married and had children. Ten years after the Purcell crimes took place, new evidence gives Hays a second chance to vindicate himself and the investigation.

Hays and West see a possible connection between the local church and the Purcell crimes. As the detectives search for one suspect and round up another one for interrogation, Woodard finds himself targeted by a vigilante group.

Wayne finds himself in a no-win situation as new clues emerge in the Purcell case. Roland wrestles with how to keep evidence secure as lawyers demand a new investigation. Amelia finds her relationship with Wayne imperilled by her writing aspirations and his jealousy.

Wayne and Roland revisit discrepancies in the Purcell case that have been hidden or forgotten over the years. Among those being re-evaluated is Tom Purcell, as well as Lucy Purcell's cousin Dan. The glitter of Amelia's book release is tarnished by a voice from the past.

Following up on new leads, Wayne and Roland track down a man who left the police force in the midst of the Purcell investigation. Meanwhile, Amelia visits Lucy Purcell's best friend in hopes of gaining insights into the whereabouts of the mysterious one-eyed man.

Wayne struggles to hold on to his memories, and his grip on reality, as the truth behind the Purcell case is finally revealed.

Two former Louisiana State CID partners give statements to investigators about a murder 17 years previous. As they look back, details of the crime, replete with occult overtones, are accompanied by insights into the detective's volatile partnership and personal lives.

Under pressure to land a suspect in the Dora Lange murder, and under threat of being replaced by a new occult-crimes task force, Hart and Cohle lobby for extra time in order to follow up on a lead that takes them from a rural cathouse to an incinerated church.

A hidden image at the burned-out church leads Cohle and Hart to a minister whose parishioners finger a scarred, tall man seen with Dora Lange. Looking to establish a pattern of murder, Cohle pores over old cases, finding a link with a woman who drowned years earlier.

Hart and Cohle hunt for their newly identified suspect, Reggie Ledoux, a meth cook who shared a cell with Lange's husband and recently skipped parole. As Hart's personal life collapses around him, Cohle immerses himself in an old criminal identity from his narco days.

Violent denouement in the forest clears the Dora Lange case and turns Cohle and Hart into local heroes. As time passes, Hart faces new tensions and temptations, and Cohle learns from a double-murder suspect that there could be more to an old case than he'd once thought.

In 2002 Cohle and Hart begin to fall back to familiar and violent obsessions. Hart exacts savage vengeance on a pair of teenage boys, and Cohle becomes convinced they left something undone in 1995. 2012, and Maggie sheds light on when Cohle quit the force.

Hart and Cohle forge a truce and probe a murky conspiracy of disappearances connected to the Dora Lange murder, a path of connections that leads to the Tuttle family. The pair then uncover a connection to an old colleague and enact a plan to draw him out.

After their interrogation of Geraci yields new info but no critical breaks, Hart and Cohle find themselves back at square one. However, a photograph, along with a homeowner's old tax records, provides the pair with a vital new lead in their 17-year-old case.

The disappearance of a city manager disrupts a lucrative land scheme and ignites an investigation involving three police officers and a career criminal who is moving into legitimate business.

Ray and Ani investigate a victim's depraved background, as does Frank, while Paul probes the Vinci PD.

Paul works the prostitute angle while Frank receives the first casualty in a secret war and steps back into a world he'd left behind.

The detail works a pawn-shop lead to close in on a suspect in the Caspere case, and Frank revisits his past to pay for his present.

Ray and Frank contemplate new life choices, while Ani and Paul follow a lead up the coast.

Desperate to locate a missing woman with intel about Caspere, Frank meets with Mexican drug dealers. Ani infiltrates an exclusive inner circle, with Ray and Paul keeping close tabs.

Ray, Ani and Paul take precautionary measures to elude detection and untangle a dark mystery. Frank deals with the fallout of his betrayal.

Frank, Ray and Ani weigh their options as Caspere's killer and the scope of corruption is revealed.