"Every night, I lie in bed and plan your murder," 12-year-old Jacob tells a boy in juvenile detention.

In Michael Cuesta's "12 and Holding," his protagonists get into situations that would be horrifying for adults, much less adolescents. And while much of the action or dialogue can be shocking, the film is a quieter, more seductive journey into the young mind than the relentless shockfest "thirteen," to which this has been compared.

After the death of his more outgoing and brave twin brother Rudy at the hands of bullies who set fire to their treehouse, Jacob (Conor Donovan) vows violent revenge. Every day he travels to juvey and issues death threats to the two guilty boys, promising that he'll kill them once their one-year sentence is finished. Jacob's parents don't quite know how to cope with the leftover twin. They say all the right things about loving him, but when they announce plans to adopt another boy, he can't help but feel superfluous once again.

His pals Leonard Fisher (Jesse Camacho) and Malee (Zoe Weizenbaum) have their own problems though. Leonard, who escaped the deadly fire, no longer has a sense of taste or smell, something that horrifies his overweight parents. He starts to eat apples -- without flavor, it's the only food with a texture he enjoys -- and exercise, which causes a rift in the family. "You just can't eat apples all the time," says Mrs. Fisher. "It's unhealthy."

Meanwhile, Malee pines for her absent father and her emotionally unavailable psychiatrist mother Dr. Chung (Annabella Sciorra), who make attentive construction worker Gus Maitland (Jeremy Renner) all the more attractive. Who cares if he's her mother's patient and easily double her age?

As a cautionary tale, "12 and Holding" is surprisingly non-judgmental and therefore effective in its matter-of-fact portrayal of kids that go to extreme, sometimes criminal lengths for morally ambiguous purposes. Besides Jacob's murderous intentions, Leonard imprisons his mother against her will to control her diet, and Malee stalks Gus, sneaking into his apartment and putting together a plan to seduce him.

The film is rated R so hopefully kids won't get the idea that these are recommended behaviors. Instead, these highly plausible scenarios are meant to be warnings to parents who fail their children in some way. The Fishers are irresponsible when it comes to diet, while the Carges find it easier to skirt around Jacob's pain. And Dr. Chung is so caught up with her practice, her mothering is reduced to shrink-speech like, "You're upset, and that's good. It's okay to cry."

Despite the three kids' struggles and the peripheral stories about their parents, "12 and Holding" never seems rushed or crowded. The film only falters a few times, like the depiction of the Fishers as food-obsessed caricatures played for laughs, but overall it maintains a nice balance between the drama and dark comedy.

Strong yet simple dialogue and engrossing performances by all three kids and Renner make "12 and Holding" an unpretentious yet intriguing film. Its exploration of troubled childhood is frighteningly convincing, yet still offers hope for parents wanting to do right by their offspring.