Ringing with the unparalleled music of the era, “Aquarius” is a sprawling work of historical fiction that begins two years before the 1969 Tate-LaBianca murders. It’s a shocking thriller, a nuanced character drama and, in the end, the story of how we became who we are today.

Sam Hodiak (David Duchovny, “Californication,” “The X-Files”), a decorated World War II vet and homicide detective, barely recognizes the city he’s now policing. Long hair, cheap drugs, rising crime, protests, free love, police brutality, Black Power and the Vietnam War are radically remaking the world he and the Greatest Generation saved from fascism 20 years ago.

So when Emma Karn (Emma Dumont, “Salvation,” “Bunheads”), the 16-year-old daughter of an old girlfriend, goes missing in a sea of hippies and Hodiak agrees to find her, he faces only hostility, distrust and silence. He enlists the help of Brian Shafe (Grey Damon, “True Blood,” “Friday Night Lights”) — a young, idealistic undercover vice cop who’s been allowed to grow his hair out — to infiltrate this new counterculture and find her.

The generational conflict between the two is immediate and heated, yet they’re both dedicated officers and soon realize the need to bring Emma home is more urgent than they foresaw. The immediacy arises because she has joined a small, but growing, band of drifters under the sway of a career criminal who now dreams of being a rock star: Charles Manson (Gethin Anthony, “Game of Thrones”).