Using the Manson Family two years before the Tate-LaBianca murders as a portal into 1960s counterculture, “Aquarius” is actually pretty groovy — a bit like a poor man’s “LA Confidential” in its revisionist look at the LAPD in a tumultuous earlier time. That makes NBC’s handling of this David Duchovny vehicle puzzling: In making all the episodes available online after its premier, it’s either an interesting experiment, charitably speaking, or an unceremonious dumping of a project whose prospects are, admittedly, uncertain. While the dawning of “Aquarius” is hardly revolutionary, the show does kick off summer with a provocative, cable-like gamble.

Duchovny plays Sam Hodiak, a World War II vet and LAPD homicide detective, asked by a former girlfriend (Michaela McManus) to help find her missing 16-year-old daughter, Emma (Emma Dumont). The girl, it turns out, has been taken by, and soon falls under the spell of, Charles Manson (Gethin Anthony), a mercurial criminal-turned-cult leader who uses his pliant followers as collateral, and still dreams of becoming a rock star.

Somewhat confused traveling in these circles, Hodiak enlists a young undercover cop, Brian Shafe (Grey Damon), to help him investigate what’s happened. Soon, though, the web widens to include other cases and conflicts (in keeping with the spirit of things, all 13 episodes were made available), including shady dealings involving Emma’s father (Brian F. O’Byrne), a heavy-hitting Republican attorney whose firm has ties to then-Gov. Ronald Reagan and president-to-be Richard Nixon.

Created by John McNamara, and representing some of his most ambitious work in years, “Aquarius” — which wisely draws heavily on the songs of the time — is big and messy, a much more direct hit on the mores of the time than something like “Mad Men,” inasmuch as this show is filtered through the neanderthal prejudices of the police at the time. So gay bars are raided, and African-American neighborhoods referred to as “the Jungle,” with Gaius Charles (“Friday Night Lights”) among the recurring players as a black activist who crosses Hodiak’s path.

If the missing-girl plot sounds wispy, McNamara cleverly employs it merely as a point of entry, and for stretches, as other plots develop, Manson is at best a bit player in the series. At its core, in fact, the show is about the tension between the older cop and his younger colleague, with Duchovny somewhat playing against type as the straight arrow, albeit one with a dark past that includes bouts with the bottle.

Manson’s ruthlessness, however — along with the blind obedience of his followers — is a constant source of menace. And if Anthony (a “Game of Thrones” alum) doesn’t always convey that messianic charisma, the series offers a taste of the how he exploited youthful alienation that paved the way for the horrors to come.

“Aquarius” also provides plenty of playful references to the time, from Hodiak shrugging when reminded about following “that Miranda thing” to one of the cops quipping that with most criminals “you’re not exactly dealing with Goldfinger.” That’s not to say all the subplots are of equal weight, but the series generally conjures an atmosphere that should draw viewers in, as if getting to see the side of “Dragnet” that wasn’t approved by the LAPD.

Given the show’s smoke-filled future, those wading in should be forewarned that “Aquarius” doesn’t offer a tidy ending, suggesting the possibility of more to come, yes, but also a lack of closure should NBC decide against going further. Then again, the network hasn’t set the highest of bars for summer (witness “Hannibal’s” improbable survival despite starvation-level ratings), which provides some hope that the show might hang on, even if it only engenders, pardon the expression, a cult following.

TV Review: ‘Aquarius’

(Series; NBC, Thurs. May 28, 9 p.m.)

  • Production: Filmed in Los Angeles by King Baby, McNamara Moving Co. and Tomorrow Studios.
  • Crew: Executive producers, John McNamara, David Duchovny, Alexandra Cunningham, Sera Gamble, Jonas Pate, Vahan Moosekian, Marty Adelstein, Becky Clements, Melanie Greene; co-executive producer, Rafael Yglesias; director, Pate; writer, McNamara; camera, Lukas Ettlin; production designer, Carlos Barbosa; editor, Timothy A. Good; music, W.G. Snuffy Walden; music supervisor, Ann Kline; casting, Laura Schiff, Carrie Audino. <strong>60 MIN.</strong>
  • Cast: David Duchovny, Grey Damon, Gethin Anthony, Emma Dumont, Claire Holt, Michaela McManus, Brian F. O’Byrne, Gaius Charles