Season synopsis
Contains spoilers for this season and earlier seasons.
Ben Caspere's murder brings three California officers into the same investigation: Vinci detective Ray Velcoro, county detective Ani Bezzerides and highway patrolman Paul Woodrugh. Caspere's disappearance also ruins criminal businessman Frank Semyon's investment in a railway deal. Ray works for Frank as well as the police, while the officers' separate jurisdictions draw them into a city where property, money and law enforcement are tightly connected.
A raid on a suspected killer's drug operation becomes a disastrous shootout. The authorities close the case, but the surviving investigators are brought back to pursue evidence that was buried. Ani infiltrates a party where women are supplied to powerful men and escapes with a missing woman. Paul traces stolen diamonds to a robbery during the Los Angeles riots. Corrupt officers involved in that robbery try to silence him, and Burris kills him after he escapes their trap.
Caspere's killer is Lenny, whose parents died in the diamond robbery. A confrontation at the station destroys the chance to preserve a confession. Ray and Frank steal money for their escape, but Ray is tracked after visiting his son and dies in the woods. Frank is stabbed and dies in the desert. Ani reaches Venezuela with Jordan and later has Ray's child. She gives a journalist the evidence, while Ray's older son is confirmed to be his biological child only after his death.