"Secret in Their Eyes" is a peculiar remake of an Argentine film that won the foreign film Oscar six years ago. What’s peculiar is that the new film has almost nothing to do with the original movie, which was just as much a love story as a crime thriller. While the Argentine version was dazzling and sleep-inducing by turns, the American version just plods along, offering a series of respectable scenes that could never bore or excite anybody.

It would be easy to write off "Secret in Their Eyes" as a standard-issue thriller, but for two performances, which are hardly routine. It’s through those performances that we come to figure out why writer-director Billy Ray ("Shattered Glass") wanted to adapt a story he apparently had no interest in telling faithfully. Like the original, "Secret in Their Eyes" follows characters over a span of time, showing how the past has a way of just hanging there and never leaving, like some free-floating, helium-filled 300-pound gorilla.

"SECRET IN THEIR EYES" Rated PG-13 Opens Friday

The noteworthy performances belong to Julia Roberts, as a criminal investigator, and Nicole Kidman, as an ambitious lawyer. Both effectively develop their characters over a 13-year span. Roberts starts off as a fairly cheerful professional, who experiences a devastating tragedy and ends up looking hollowed out, devoured by grief. Kidman is called upon to show a more subtle transformation, that of a woman who has come into her power, who has become comfortable possessing authority.

But at the center of the film is Chiwetel Ejiofor, an FBI investigator from New York, who returns to Los Angeles after 13 years away, convinced that he has cracked an unsolved murder. Ejiofor, a commanding presence in many films, including "12 Years a Slave," adopts a frazzled, jumpy quality that doesn’t wear well over the course of almost two hours. The movie gives him a sprinkling of gray hair for the later scenes, but aside from that, his character doesn’t change at all. Maybe that’s the point — he has remained frozen from the time of the big, failed case.

The movie starts in the present but keeps flashing back for long periods, telling the story of a crime and of the ensuing police investigation. But this structure comes with a built-in problem, namely that we know going in that nothing from 13 years ago will solve anything. Although this doesn’t rob the past scenes of interest, it does take away some of the potential excitement.

"Secret in Their Eyes" is at its best when it stays focused on the people. One of the most excruciating scenes of the movie year comes when Roberts goes off to investigate a routine homicide and finds that the victim is someone close to her. What follows is an anguished, almost frightening plunge into the depths of grief. Who knew that Roberts could take us there? And what an impressing thing it is, that Roberts allowed herself to appear on screen without the armor of glamour, not looking like a movie star but like a mere mortal.

The Argentine version, by the way, took place over a span of 25 years, a more poetic stretch of time representing a huge portion of the characters’ adult lives, but difficult to convey on screen while using the same actors. By shortening the stretch to 13 years, the American film makes things more plausible — and yet with every improvement, some magic is lost. In "Secret in Their Eyes" we get a story that has been improved almost to the point of nonexistence.

That’s the mystery of art, the delicate and intricate alchemy of success. Fix all the flaws and you can end up wrecking the whole thing.

Review by Mick LaSalle, San Francisco Chronicle