Series Premiere. The lead investigators in a macabre 1995 murder relive the case in the wake of new info.

Under pressure to land a suspect, Quesada warns Hart and Cohle they might be replaced by three detectives from a new occult-crimes task force. The pair lobbies for extra time in order to follow up on a lead that takes them from a rural cathouse to an incinerated church. With his marriage to Maggie already strained by work, Hart ends up finding respite outside of home.

A hidden image at the burned-out church leads Cohle and Hart to Joel Theriot, a tent-revival minister whose parishioners finger a scarred 'tall man' seen with Dora Lange. Hart gets sidetracked after Maggie sets Cohle up with a friend at a C&W bar. Cohle pores over old case files, finding a connection with a woman assumed to have drowned years earlier.

Hart and Cohle hunt for their newly identified suspect, Reggie Ledoux, a meth cooker who shared a cell with Dora 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, contacting an East-Texas biker gang known to deal with their primary suspect.

A 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 much more to an old case than he'd once thought. In 2012, Gilbough and Papania put their cards on the table, presenting disturbing new intelligence.

In 2002, Cohle and Hart begin to fall back to familiar and violent obsessions. Hart is reintroduced to a former prostitute he met during the Lange investigation. In 2012, Papania and Gilbough question Maggie, now divorced from Marty, about Cohle and Hart during 2002, the year their relationship fractured and Cohle quit the force following a suspension.

After Marty is shown a harrowing piece of evidence, he and Cohle forge a truce as they probe a murky conspiracy of disappearances connected to the Dora Lange murder, a path of connections that leads to the Tuttle family. Hart reconnects with Maggie, who later pays Cohle a visit. Cohle and Hart uncover a connection to an old colleague and enact a plan to draw him out.

Season One Finale. After their interrogation of Geraci yields new info but no critical breaks, Hart and Cohle find themselves back at square one. However, a seemingly arbitrary detail in 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 two men pursue the lead to an apocalyptic confrontation.