The demon child lives in "Joshua"

Joshua may never replace Damien as a synonym for demon child, but George Ratliff's "Joshua" certainly introduces the possibility. Spooky, relatively realistic, grounded in psychology rather than displays of gore, it could be just the thing to rejuvenate the fading horror genre.

The movie begins with what appears to be a mild case of sibling rivalry. When Wall Street businessman Brad Cairn (Sam Rockwell) and his wife, Abby (Vera Farmiga), welcome a baby girl into their Manhattan home, their 9-year-old genius son, Joshua (the wonderfully poker-faced Jacob Kogan), instantly becomes resentful. He gradually undermines what had seemed to be a functioning family.

Abby is suffering from depression and goes off her meds. Brad starts losing it at the office, offending his boss (Michael McKean) and toying with Internet porn when Abby loses interest in sex. Brad's born-again mother, Hazel (Celia Weston), turns fanatical about baptizing the kids, while Ned, a musical-comedy-loving uncle (Dallas Roberts), quietly discovers the depths of the boy's manipulative spirit.

Joshua succeeds partly because his problems appear to be the problems of many preadolescents. He doesn't take to playing soccer in Central Park and asks Brad if he dislikes his "weird son." At a hilariously horrible school concert that quickly turns into "The Gong Show" for most of the talentless participants, Joshua stands out as a pianist with his own precocious, morbid sense of style.

When the boy suddenly decides to give away his expensive toys ("I'm starting over"), he becomes obsessed with Egyptian theories about the afterlife. He's also encouraged by his grandmother to read some of the more violent passages in the Book of Joshua. In one particularly creepy scene, he insists that "someone died in this apartment" as his parents try to make sense of his ramblings.

The script by Ratliff and newcomer David Gilbert is always on the edge of becoming ridiculous, yet the cool plot twists and the carefully chosen actors rein it in whenever it threatens to spin out of control. Rockwell, Roberts and Farmiga take their work seriously and never behave with condescension toward the horror genre.

Like Ratliff's 2001 documentary, "Hell House," which memorably took on a fundamentalist Halloween fright show, "Joshua" doesn't have much use for the more coercive forms of religion. And there is no supernatural explanation for Joshua. He's just a very mixed-up kid — and quite scary when he wants to be.

John Hartl: johnhartl@yahoo.com