'Go for Sisters' (unrated)

For a good while, writer-director John Sayles tricks you into thinking Go for Sisters is a crime thriller — the story of two old high school friends who hire a retired LAPD detective to help them find a person gone missing. Their search takes them to some dangerous places in Tijuana — drug dens, sex shops operated by crooked cops, the headquarters of a criminal kingpin — and the movie generates considerable suspense in a few stretches, something Sayles is not known for doing.

But by the end of the film, the plot fades into the background — the mystery is a MacGuffin and is resolved in a rather perfunctory way — and the characters take control of the movie. Go for Sisters is about three people with a common goal who join forces for self-serving reasons. Bernice (LisaGay Hamilton) is a strict parole officer who has zero tolerance for any kind of violation. She’s cold and methodical and unforgiving, the way people become after years of hearing sob stories from liars. But in a rare moment of kindness, she gives one of her charges, the recovering drug addict and dealer Fontayne (Yolonda Ross), a break so she won’t lose her job at a diner.

Bernice and Fontayne used to be inseparable as teenagers — the film’s title refers how they were so tight, they could pass for sisters — until a boy came between them and wrecked their friendship forever. Still, vestiges of their bond remain. When Bernice’s estranged son Russell goes missing and becomes the main suspect in a murder, she turns to Fontayne and asks her to re-enter the criminal underworld she left behind in hopes of getting a lead on Russell’s whereabouts.

Once Edward James Olmos enters the story as Freddy, a former cop who is going blind and agrees to help the two women (for a fee), Go for Sisters becomes a study of an exceedingly odd trio who wind up making a formidable team despite their radically different backgrounds. The strained intimacy between Hamilton and Ross gradually gives way to a renewed friendship: Through their desperate (and dangerous) adventure, they learn to forgive each other and reconnect with what drew them together as adolescents. Olmos, exuding a seen-it-all wisdom and authority, is as commanding here as he was on Battlestar Galactica. Freddy is a resourceful and experienced detective who knows how to think on his feet and deal with dangerous thugs. Even though he has no official jurisdiction in Mexico, he manages to outwit defiant, arrogant perps using simple tricks and head games instead of violence. His body may be crumbling, but his mind remains razor-sharp.

Go for Sisters is peppered with great performances by unknown actors who pop up for a single scene, such as a heroin dealer who can’t be bothered to stop munching on some eggrolls while making a deal, or a bartender at a club that the missing man frequented who has obviously developed a romantic interest in him. Sayles, as is his wont, uses his setting as a character, a maze of pitfalls and potential dead-ends with menace lurking under every shadow (“This isn’t Mexico,” Freddy says about Tijuana. “This is like a theme park for bad behavior.” The tough turf will prove to be just what the two old friends need to reconcile and for Freddy to find his inner fire again. Go for Sisters is minor Sayles, and the movie occasionally meanders. But the characters stay with you, particularly Bernice and Fontayne, whose relationship is beautifully transformed over the course of the film. Sometimes, bad things can lead to good.

Cast: Edward James Olmos, LisaGay Hamilton, Yolonda Ross, Harold Perrineau, Hector Elizondo, Isaiah Washington.

Writer-director: John Sayles.

Producers: Edward James Olmos, Alejandro Springall and Peter Bobrow.

A Variance Films release. Running time: 122 minutes. Vulgar language, brief violence, gore, adult themes. In English and Spanish with English subtitles. Opens Friday Dec. 13 in Miami-Dade only: Coral Gables Art Cinema. Director John Sayles will participate in a live video-link Q&A following the 7 p.m. screening Friday. For more information, visit www.gablescinema.com.