A gritty 1960s cop drama about LAPD detective Sam Hodiak and his trainee, who must deal with gangs, brutal crimes, changing times, family crises and unhinged manipulative small-time crook Charles Manson, who's slowly building his cult.
Hodiak receives some disturbing fan mail as Charmain takes a dangerous plunge undercover and Brian discovers Roy's true intentions. Ken takes aim at Hal as Charlie fears an old prison mate is back to collect a debt.
Charlie cooks up a plan for Ralph and his crew; Hal wakes to a nightmare; and Hodiak gets leverage for his son.
Charlie bonds with a Beach Boy, while "Tex" joins the Manson Family. Hodiak and Grace tread familiar territory as Brian takes a stab at a killer and gets rewarded for his sharp work.
On the day of Martin Luther King, Jr.'s assassination, Hodiak must investigate a murder in a black neighborhood while trying to prevent an imminent riot. In the midst of the crisis in the black community, Kristin's involvement with the Black Panthers drives a wedge between her and Shafe's marriage. Meanwhile, Charmain brings the drug case to a close and discovers the full cost of undercover work.
Internal affairs turns up the heat on Hodiak, but a tragedy interrupts the investigation. Meanwhile, Dennis Wilson's courtship with Emma ignites jealousy in Manson. Dennis takes Emma and Manson to meet a record producer who lives at 10050 Cielo Drive- the future home of the Tate family.
While Shafe's addiction problems mount, Hodiak helps an old war buddy find his blackmailer. Meanwhile, Karn gathers information to use against Bobby Kennedy and Grace finds a new love for politics.
Manson and the Family receive two surprises: one a blessing, one a threat. As Hodiak tries to investigate a new clue in the case of the photographer killer, a series of roadblocks forces him to take a proactive measure. Meanwhile, Grace makes plans for Emma. A shootout between the Black Panthers and LAPD reverberate in Shafe and Kristin's marriage.
Shafe, alone at the bloody Tate crime scene, is confronted by his own demons. As Manson searches for a missing Emma, he ends up on Hodiak's doorstep. Meanwhile, Ken Karn goes to new levels for international diplomacy.
Sharon Tate begs for her life but Sadie has no mercy. Manson tries to track down Dennis Wilson. Meanwhile Hodiak finds Emma in a sanatorium, but will need help to get her out. While, an unemployed Ken Karn reunites with an old friend.
Ken and Emma reconcile but Emma wants to find Charlie. At the expense of Charmain's career, Hodiak is determined to find the truth behind Bunchy's murder. Meanwhile, Shafe sees an old friend at rehab.
Changes within the police department land Hodiak back in hot water with Internal Affairs, which forces him to adjust to a neutered role in the precinct. Meanwhile, the Manson family's misfortune seems to take a turn for the better when Terry Melcher arrives and wants to record Charlie's music.
Hodiak decides to take matters into his own hands and shows up on the doorstep of the mysterious serial killer who has been sending him obscene pictures. Meanwhile, Manson sends Bobby, Mary and Sadie to go to extreme measures to get money from Gary Hinman.
A newly "retired" Hodiak tracks down the serial killer who has been tormenting him for months, without the protection and authority of his police position. Manson sends Tex, Sadie, Emma and Patty to 10050 Cielo Drive, where they are swept up in one of the most infamous crimes in the country's history. (Series Finale)