There’s no mystery surrounding how “I Am the Night,” TNT’s new truthy-crime mini-series, came to be. The director Patty Jenkins met and befriended Fauna Hodel, author of a memoir, “One Day She’ll Darken,” about her difficult youth. Not quite a decade later Jenkins made “Wonder Woman,” which made more than $821 million. Et voilà: “I Am the Night,” a long-gestating project “inspired by the life of Fauna Hodel” with Jenkins as a director and executive producer.

It’s less clear how the six-episode mini-series (beginning Monday), which was created and written by Jenkins’s husband, Sam Sheridan, and stars her “Wonder Woman” collaborator Chris Pine, turned out to be such a lackluster and derivative affair. But we can speculate.

Hodel’s book was primarily the story of her childhood and teenage years, when she grew up with African-American adoptive parents and thought she was mixed-race, although she was white. It had a sensational kicker: When she learned the truth about her biological parents, she also learned that one of her grandfathers was George Hodel, a prime suspect in the infamously gruesome and unsolved Black Dahlia killing in 1945.

So the story had two currently hot hooks: struggles with race and identity, on one hand, and a lurid real-life murder mystery, on the other. It was out of balance — George Hodel and the Black Dahlia case were a minor, if highly promotable, part of the book — but screenwriting could fix that.

The result is a bland hodgepodge. Fauna Hodel’s tale of alienation and self-discovery is there in a condensed, movie-of-the-week iteration, with the details softened, perhaps to make her a more congenial heroine. Sharing equal space with it is the material that Sheridan, whose previous credits include two episodes of “SEAL Team,” appears to have been more excited by: an entirely invented, entirely synthetic Los Angeles-noir mystery plot, hashed together from bits of “L.A. Confidential,” “Chinatown” and “The Long Goodbye.”

To make it work, Sheridan inflates the celebrity gynecologist George Hodel (Jefferson Mays) into a mythic, city-straddling figure along the lines of John Huston’s character in “Chinatown.” When Fauna (India Eisley), 16 but intrepid, comes to Los Angeles in 1965 looking for answers about her past, he’s able to pull strings everywhere from the police department to the city’s newsrooms to the National Guard to help shut her down.

Chris Pine plays a down-and-out journalist named Jay Singletary who joins forces with Fauna Hodel.CreditClay Enos/TNT

An even bigger invention is Pine’s character, a down-and-out journalist named Jay Singletary whose career was ruined when George Hodel sued him for libel. (Jay was covering the trial when Fauna’s biological mother accused George of sexual abuse, a detail drawn from history.) Now obsessed with exposing George, Jay crosses paths with Fauna and they warily join forces.

Inventions don’t equal inventiveness, though, and everything about the Los Angeles mystery story feels reheated. Connie Nielsen is forced to put on a head scarf and go full Norma Desmond as one of George’s former wives, while Dylan Smith twitches and leers in the Peter Lorre role as George’s pervy underling.

Leland Orser (currently excelling in “Berlin Station” on Epix) plays a newspaper editor who assigns stories from his bar stool, which reads as a cliché here even if it sometimes happens in real life. When the dialogue isn’t flat and mechanical, it veers into risible noir-speak. (Picking a fight, the hard-boiled hipster Jay says: “If you’re feeling froggy, we can do this dance. Pick a lily pad.”)

That should be a tip-off that Pine, a wonderful film actor who hasn’t done a lot of TV, doesn’t have much of a character to play either. Jay’s two notes are cocaine-fueled post-traumatic anger — he saw combat at Chosin Reservoir in the Korean War — and stoic nobility, alternating until the story doesn’t need him anymore and he fades away. Pine brings his relaxed charisma and presence to the role, and he’s the one reason to watch.

But he can’t really make much out of Jay, a cardboard construct whose demons we have to take on faith. Sheridan tries to address this by giving Jay dreams in which fur-hatted Chinese soldiers surround him in his apartment or his jail cell, an idea that’s as bad as it sounds. (In a similar vein, scenes of naughty parties at George’s house and a clothes-rending happening only prove how hard it is to depict Hollywood debauchery without inducing giggles.)

Eisley probably gets more screen time than Pine, but Fauna feels like a secondary character even as the story is channeled through her. That’s partly because of Eisley’s performance — she shuffles a small deck of expressions and emotions — and partly because the scenes involving her embittered but protective mother (Golden Brooks) and her other African-American relatives are pretty perfunctory. The mystery plot is no more original, but it’s delivered with more conviction. (When the 1965 Watts riots are introduced late in the series, it’s just to complicate the characters’ movements before the big finish.)

There’s no reason you can’t do a great Los Angeles noir predicated on race — Carl Franklin did it in 102 minutes in “Devil in a Blue Dress” (1995). That’s about the running time of the last two episodes of “I Am the Night” — also, as it happens, directed by Carl Franklin. (Jenkins and Victoria Mahoney split the others.) There’s a math lesson in there somewhere.