A tale of a child's illegal journey from Mexico to his mother in California, Under the Same Moon (La Misma Luna) is mawkish, often predictable and unabashedly sentimental. It is also very effective. You might hate yourself in the morning, but this tearjerker is almost as moving as it is shamelessly manipulative.

A hit with audiences at the 2007 Sundance Film Festival, the picture chronicles the travails of 9-year-old Carlitos (Adrián Alonso). The scrappy little boy pines away for his mother, Rosario (Kate del Castillo), who left her native country four years ago to make a better life for her son working as a domestic in Los Angeles. Carlitos, who lives with his grandmother, yearns to join his mom; the only connection between mother and child comes with a phone call every Sunday morning.

Carlitos resolves to travel to the United States to see his mother. Since his grandma is coughing an awful lot throughout the first act -- subtlety isn't a strong suit here -- we know it's only a matter of time before she dies and thereby prompts the boy to set out on his trek.

In the process, Carlitos endures the incompetent smuggling of two Mexican-American college students (one of whom is played by Ugly Betty's America Ferrera), a junkie who tries selling the boy to sex peddlers and a raid by the Immigration and Naturalization Service. Director Patricia Riggen and screenwriter Ligiah Villalobos pile on everything short of an evil, top-hatted gringo tying Carlitos to the train tracks. The rapid succession of threats reminds me of Thelma Ritter remarking on Ann Baxter's tale of woe in All About Eve: "What a story! Everything but the bloodhounds snappin' at her rear end."

Each time Carlitos hurtles toward calamity, however, the filmmakers allow for a deus ex machina to smooth things over. Despite the dangers seemingly everywhere for the young boy, Under the Same Moon dilutes its own suspense by taking the easy way out of nettlesome situations. A saintly Mexican woman turns up fortuitously to take Carlitos under her wing, a roadside diner is hiring a dishwasher at the exact right time, and so on and so on.

The filmmakers load the proverbial dice in other ways, too. Riggen and Villalobos evidently want to impact the debate over illegal immigration by placing human faces to the immigrant plight, but they come close to demonizing white Americans. The movie's sole positive Caucasian character -- and she gets maybe a minute of screen time -- is one of Rosario's two employers. The other employer, it should be noted, cheats the hardworking woman out of her pay and then fires her unceremoniously.

Nevertheless, there are emotional rewards for audiences willing to approach Under the Same Moon as purposely overwrought melodrama and not as, say, an edifying treatise on illegal immigration. Earnest performances certainly help. Alonso makes an engaging lead, while del Castillo provides shadings of ambivalence to what easily could have been an archetypal character. Best of all is Eugenio Derbez as a traveling laborer who takes on a grudging fondness for Carlitos. Derbez's character arc, in fact, might be the most compelling part of Under the Same Moon.

As is so often the case with Fox DVD releases, the screener supplied does not represent final product. That precludes a fair assessment of picture quality. With that disclaimer, I will note the picture generally boasted strong lines, rich details and a solid color palette. Slight grain was detected in a few nighttime scenes, and there is a moment of pixilation toward the film's end.

Audio is impossible to judge fairly because the review screener does not represent final product. That said, the 5.1 Dolby Surround track, which is in Spanish, was serviceable, albeit with little dramatic use of rear speakers. Optional subtitles are in English, but the screener provided for review contained only English for the hearing-impaired.

The Making of La Misma Luna (26:23) has a relaxed, modest feel that puts it several notches above your typical promotional featurette. Not as successful is La Misma Luna: Mural Documentary. The 11-minute, 23-second piece chronicles how Fox Searchlight commissioned a team of muralists to make a mural promoting the movie in East L.A.

If you remove Under the Same Moon from the hot-button issue of illegal immigration, the movie succeeds on its own terms -- as an affecting, if overwrought, melodrama. It's a yarn as old as storytelling itself: a child in peril yearns to be reunited with his beautiful, hardworking mamma. You never doubt where you're heading here, but director Patricia Riggen is skillful enough to keep you (mainly) interested.