"How do you know it's a lie?" one character asks near the climax of the riveting "Everybody Knows," to which comes the response, "How do you know it's true?"

That's the dilemma of the movie (and, you know, life). Laura (Penélope Cruz) and her kids have returned to her tiny Spanish hometown for her sister's wedding, during which her teenage daughter is kidnapped.

Suspicion immediately falls on strangers who were at the wedding to shoot a video, but, as Cruz and friends try to figure out what's going on, afraid to involve the police, the web of suspicion tightens to include wedding guests, her daughter (maybe the kidnapping was a setup?), other family members, her mysterious husband and, finally, even the man she has trusted most, Paco, a former lover/family servant who is played by Javier Bardem.

Paco is the moral center of the movie, and the fact that Bardem is Cruz's real-life husband adds extra zing to scenes in which the tortured pair search for the missing girl.

The tension also builds thanks to the skill with which writer/director Asghar Farhadi reveals and withholds information. The early scenes are dizzying, introducing us to 20 or so characters in the first 10 minutes, and the story proceeds breathlessly, with no hand-holding, as Farhadi skips over key events, creating little mysteries and expecting us to be able to keep up.

In lesser hands, that might come off as artificial, but in a movie that's literally about the danger of hidden information, it feels just right: The people in the movie are keeping secrets from each other, and "Everybody Knows" is keeping secrets from us.

By now, it's clear that the prolific Farhadi, whose "A Separation" and "The Salesman" both won foreign-language Oscars, has a thing. He makes family dramas that are driven by the secrets even loved ones keep from one another, and, in the end, his films are usually about class.

Here, the divide is between Laura's comfortable extended family, who are almost like rulers of their town, and Paco, who labored to turn a piece of land he bought from Laura's family into a successful vineyard but may be asked to sacrifice it as a ransom.

The ending is not as elliptical as Farhadi's previous films, a decision that could make "Everybody Knows" more popular with moviegoers (casting big stars helps there, too), but that makes it feel slightly less assured. As he fills us in on everything — whether it was an actual kidnapping, who was involved, whether the daughter lives — it begins to feel like the pieces are falling in place too neatly.

Fortunately for the audience, Farhadi gets back on track with the final sequences, which suggest that although the movie has uncovered many secrets, a whole new set of them has just emerged.

Chris Hewitt • 612-673-4367