‘Broken City’: Star power fixes broken plot | 2½ stars

Mark Wahlberg has fallen comfortably into the role of Generic Hero With a Troubled Past (“Ted,” “Contraband”). Russell Crowe is versed in playing Menacing Authority Figure (“Les Miserables”).

The inevitable showdown between these archetypes is the reason to see “Broken City,” a zigzagging thriller that is equally satisfying and forgettable.

Wahlberg plays Billy Taggart, a New York City detective booted off the force years ago for gunning down a rape suspect. Now he functions as a low-rent private eye, snapping pictures of unfaithful spouses and then berating his deadbeat clients into paying for them.

But an invitation to city hall proves lucrative. Mayor Nicholas Hostetler (Crowe) — who had a hand in Taggart’s forcible retirement — offers him an assignment: Find out who is having an affair with his high-profile wife (Catherine Zeta-Jones). Complicating the issue is the mayoral election mere weeks away. Idealistic challenger Jack Valliant (Barry Pepper) is leading in the polls, despite the mayor deeming him “a rich Connecticut carpetbagger.”

These are just the basics of director Allen Hughes (“From Hell”) and rookie screenwriter Brian Tucker’s mazy project. The story is brimming with lies, compromises and double-crosses. Politics as usual, so to speak.

For a while, the movie becomes overloaded with characters and their thorny backstories. Taggart lives with Natalie (Natalie Martinez), an aspiring actress who also happens to be sister of the rape victim from his final official case.

Their affiliation seems more honor-bound than romantic. This leads to the movie’s best scene, when the blue-collar Taggart joins her at a hipster premiere. But it also provides the picture’s clunkiest line: “It’s not every day that your girlfriend stars in her first indie film.”

That relationship (and a few others) is jettisoned by the third act in favor of the marquee matchup between the male leads. Crowe, in a spray tan and goofy haircut, appears too wispy early on, as if he’s trying to distance himself from the “Gladiator” mold of invincible idol. He eventually finds the right balance of media-friendly politician and back-alley thug.

“Everything I do is for this great city,” he declares.

Wahlberg has the chiseled look of a man unafraid to get his hands dirty — even if that means digging in people’s trash for incriminating receipts. The drama builds to a slick confrontation admirably more dependent on maneuvering and morality than fists and pistols.

Not all of it adds up. What exactly is Valliant’s connection to a faked burglary that necessitates a bathtub beat-down by the police commissioner (Jeffrey Wright)? And much of the plotting is plenty familiar, done with greater resonance in superior efforts like TV’s “The Killing.”

But the peripheral noise gives way to the promised face-off. Politics vs. law enforcement. Crowe vs. Wahlberg.

“Proof can be a powerful weapon,” the film’s poster boasts.

So can a marquee cast full of Oscar firepower.