By Dan Chaon. Ballantine. 356 pp. $24.95

About a third of the way through Dan Chaon's remarkable first novel, You Remind Me of Me, a 6-year-old boy named Loomis Timmens is abducted from his grandmother's backyard on a sunny June morning in 1997. In a more conventional narrative, this is where the plot would kick into overdrive. We would get a blow-by-blow account of the police investigation, an unsparing portrait of the increasingly anguished parents, perhaps a broader portrait of the community in which the nightmarish event occurred. The mystery would propel the book relentlessly forward, toward a clear-cut resolution.

Chaon does something much more interesting. He devotes a couple of pages to the initial search for Loomis, then abruptly backtracks four years to fill in some background on Nora Doyle, a mentally unstable woman who gave up her first child for adoption in 1966. Then he hops forward three more years to chronicle the journey of Jonah Doyle, Nora's second child, from Chicago to St. Bonaventure, Neb., where he hopes to meet a man named Troy Timmens. According to documents Jonah has received from an investigative agency called PeopleSearch, Troy is "Baby Boy Doyle", the child the unwed 16-year-old Nora believed she was in no position to raise and had abandoned for his own good 30 years earlier. Troy, a bartender and small-time pot dealer, also happens to be Loomis's father.

For the next 100 or so pages, Chaon methodically chronicles the peculiar convergence of Nora's two sons, the one she raised and the one she gave up for adoption. Jonah, an emotionally needy, socially awkward man whose face is disfigured by scars -- as a boy, he was attacked and almost killed by the family dog -- decides not to confront Troy directly. Instead he worms his way into his brother's life, finding work in the kitchen of the restaurant where Troy tends bar, interrogating mutual acquaintances, showing up at Troy's house unexpectedly with bags of groceries. To explain his sudden appearance in a backwater town like St. Bonaventure, Jonah creates a heart-rending fictional biography for himself, telling his co-workers that he's trying to start a new life after surviving a tragic car accident that killed his pregnant wife.

These early encounters between the two brothers -- one knowing the truth of their blood connection, the other still in the dark -- provide some of the freshest and most powerful scenes in the novel. When the brothers meet for the first time, the warmth of the other man's greeting leaves Troy bemused: "'I'm really pleased to meet you,' Jonah said, with a nervous, earnest enthusiasm, as if Troy were someone he had heard of, someone famous." As the two men work together in the downscale tavern known as the Stumble Inn, Troy grows increasingly irritated by Jonah's furtive scrutiny and puzzled by the strange undercurrent passing between them: "He was aware of Jonah, too. Jonah's eyes on him. He'd turn to look over his shoulder and the prickly feeing on the back of his neck would intensify for a moment. . . . Something was wrong with the kid, something beyond the scars, but he wasn't sure how to pinpoint it. . . . Troy had the paranoid idea that maybe Jonah was an undercover agent for the DEA or something, planted here to spy on him."

The slow, painful revelation of the bond between Jonah and Troy forms the heart of You Remind Me of Me, and it is a tribute to Chaon's considerable gifts that the truth, when it comes, deepens as many mysteries within the novel as it solves.

Chaon is an accomplished writer of short stories -- his second collection, Among the Missing, was a finalist for the National Book Award -- and You Remind Me of Me is, in some ways, a story writer's novel. Despite its fragmented, jumpy structure, the book has an unnerving tightness of focus, rarely digressing from its central themes or shifting its gaze from the four central characters -- Jonah, Troy, Nora and Loomis -- all of whom seem like variations on a single melancholy personality. This is deliberate, of course -- the entire book can be seen as an extended meditation on family resemblances -- but it sometimes feels as if Chaon has attempted to transfer Poe's classic doctrine of the "Single Effect" from the narrow confines of the short story to the larger field of the novel. In doing so, he takes a considerable risk of producing a grim and airless narrative, devoid of subplot, comic relief or social commentary.

Yet Chaon has written an apparently claustrophobic novel that feels paradoxically large, generous and, ultimately, quite moving. This is thanks in no small part to his vivid, unadorned prose, which manages at once to be precise and dreamlike, as in this description of Troy's ex-wife: "Carla liked to sprawl. Her sleeping pose was like a cheerleader, frozen in mid-leap, like someone falling backward into water." Mainly, though, the book succeeds because it makes us feel its characters' pain and inhabit a world in which desperate measures often seem like the only ones available. *

Tom Perrotta's most recent novel is "Little Children."