Another week, another botched film noir.

First, a good performance from Ben Affleck is squandered to give Adrien Brody something to do in Hollywoodland. Now, James Ellroy’s pulpy entwinement of shame, fame and greed falls prey to director Brian De Palma’s horror-show operatics in The Black Dahlia.

This hard-boiled tale is marginally better than Hollywoodland and not just because it at least explains and shows the Hollywoodland sign. The performances aren’t as good, but it’s also not terminally slow and flirts with marrying Ellroy’s labyrinthine mystery of Hollywood disposability to De Palma’s psychosexual favorites — the ideas of doubles and iconography, making memory a fetish and the impotence men feel when they can’t be women’s protectors and providers. De Palma’s textbook plays on perspective and camera tricks also jolt the film throughout the narrative.

But rather than meticulously working through the multi-faceted story, De Palma and writer Josh Friedman get lost in the maze and try to run their way to the end. Dahlia’s comically abrupt ending is all flimsy flashbacks and explanations for a fictional take on a real-life murder.

The only of the four leads to not employ some sort of vocal affectation, Josh Hartnett plays “Bucky” Bleichart, a boxer turned rising star in the Los Angeles Police Department. Bucky is promoted to the prestigious Warrants department after top brass play him as a PR card in a publicity-stunt match with former heavyweight, and established LAPD hotshot, Lee Blanchard (Aaron Eckhart, underused and raising his voice to hit Jimmy Cagney’s wisenheimer pitch).

Near to a stakeout that ends in gunfire for Bucky and Lee, police find the bisected body of Elizabeth Short (Mia Kirshner, heartbreakingly fragile in screen-test and stag-film flashbacks). An actress connected with L.A.’s lesbian underground, Short becomes front-page news that prompts the department to put numerous detectives, even those in Warrants, on the case of her murder.

Unflappable Lee becomes unhinged with obsession while Bucky beds a socialite who could be the killer (Hilary Swank, with a vaguely British accent). Then there’s the duo’s odd triangle with Kay (Scarlett Johansson, more pert than her typical huskiness), who also has a checkered past.

Known for filming graphic gore as lovingly as his nubile actresses, De Palma restrains himself for the better portion of a movie that’s wonderfully designed and filmed — whether it’s gauzy shots of Johansson or Hartnett’s trek into a hellish shantytown at the foothills of the Hollywoodland sign.

If only the story could have the same grimy buildup as the windows through which DePalma looks with voyeuristic glee. Like a teakettle impatient to explode, De Palma makes the final act a graphic tumble into mayhem that focuses only on tragedy’s sex and blood, not its mental anguish.

Somewhere, there’s a tough, memorable, visually majestic multi-faceted story with femmes fatales, gruesome secrets and the responses of those facing corruption of the law and of the soul. But it’s Curtis Hanson and Brian Helgeland’s adaptation of Ellroy’s L.A. Confidential, not De Palma’s take on The Black Dahlia.