In her sophomore outing, Lina Chamie ("Tonica Dominante," 2000) revels in intricate nonlinear execution. Pic doesn't so much run out of steam as wear out its welcome. But despite diminishing returns in final stretch, poignant punch line is worth waiting for.

In frantically arrayed jump cuts, panicky college lit professor and author Heitor (Marco Ricca) runs out into the street, unsure which way to turn. He's just had an upsetting conversation with his much younger girlfriend, Julia (Alice Braga), a lovely actress who left the stage to become a veterinarian.

As their simple phone conversation turned sour, he accuses her of preferring a handsome actor her own age, Thiago (Fernando Alves Pinto). Seized with regret, Heitor hops in his car, but traffic flow is only a notch better than gridlock.

From the remembered moment they met at a rambunctious, quasi-nude theater performance, pic consists primarily of Heitor reflecting, in flashback, on the sweet contours of his and Julia's now-jeopardized romance of three years.

Stuck behind the wheel, Heitor imagines Thiago reaching Julia first and taking his place. En route, Heitor encounters billboards and graffiti that, like his car radio, seem to be speaking directly to him -- a philosophical stick-up man, poor urchins, an unfortunate pooch and an extra-large helping of his own memories.

Toying boldly with the juxtaposition of sound and image (helmer holds a master's degree in music), venture is unafraid to pair otherwise silent footage with everything from Schubert to Satie to the distinctive theme music from Tom and Jerry cartoons.

Mix of comic and tragic may not be to all tastes, but helmer has a vision to impart, enhanced by the teeming expanse of Sao Paulo, identified as Latin America's most populous city after Mexico City.

While few would debate the advantages of falling in love, pic does indirectly question the global wisdom of the automobile as a means of efficient transportation.

Camera (color), Katia Coelho; editor, Andre Finotti; production designer, Mara Abreu; sound (Dolby), Louis Robin. Reviewed at Cinematheque Francaise, Paris, May 11, 2007. (In Cannes Film Festival -- Critics' Week). Running time: 86 MIN.