Jamboree, a story about Boy Scouts and their fathers, opens on such a disarmingly simple note that a grownup reader may think he has strayed into the young adult section of his bookstore: Six families assemble one September morning on a church parking lot in northern New Jersey and set out in a caravan for a jamboree of regional Boy Scout troops on the Jersey shore. But do not be deceived. Michael Upchurch, in his first novel, swiftly makes a claim on the most sophisticated of readers.

Carload by carload, and then one by one, fathers and sons are introduced. By the time Troop 431 reaches the campsite at Sandy Hook, certain of their number have been marked for attention. The most singular of them is Chris Castle, the 14-year-old son of a Vietnam war casualty and his widow, who have remarried. Her new husband, an Englishman named Ian Davies, is dutifully along on the jamboree.

The three of them -- Ian, Laura, and Chris -- are a family of wary and self-reliant people: Ian because he is in a strange land, Laura because she has endured the solitude of a military wife and then the bereavement of a war widow, and Chris because he is an only child, and had been uprooted to live in England for three years to boot.

Chris keeps to himself, prefers his own company and, in a pinch, that of grownups. He maintains a pose that is "cool, watchful," and -- necessarily -- judgmental. Observing his fellow scouts and their fathers on their way to Sandy Hook, he wonders when "would these people ever reveal themselves, having through motions of friendliness and openness and assumption and intrusion so effectively hidden themselves at the outset -- or were they really as simple as they made out they were?"

Of course they are not so simple, as Jamboree presently demonstrates. But such superiority is Chris Castle's cross to bear, and arguably it is Michael Upchurch's too. Though this novel maneuvers with ease and polish from one character's vantage to another's, the presiding judgment unmistakably is Chris'. He is a young man older and wiser than his years, but neither so wise or so old as he imagines.

The scoutmaster, Jim Gough, is a martinet and a loudmouth, one of those familiar American men who bring to fatherhood the sensitivity of a master sergeant. Gough is in thrall to his wartime memories. A year of idle service on a sunny island where no shots were heard has been overwhlemed by "a quarter of a century of passionate absorption in war books, documentaries, government-authorized footage, encyclopedias of aircraft, war vessels, tanks, guns, armaments, and uniforms of every kind, until his own "war year" was almost eclipsed, could not be distinguished from a dream anymore."

Gough's reverence of might, alas, has not been lost on his son, Jim Jr., the oldest scout in the troop and thus the most self-conscious. Jim Jr. is dogged by failure and all but paralyzed by the fear of it, taunted by his contemporaries and browbeaten by his father, sullen and defiant by turns -- and in the end, violent.

The other character who looms large in this outing is, perhaps by design, Gough's opposite, a mouse of a fellow named Mr. Bray, who has a couple of rambunctious twins in tow. Mr. Bray (he seems to have no first name) is the manager of a "negligible branch" of the local bank and so timid that he tunes in to televised sporting events every weekend for no reason other than to brief himself for the next Monday morning's inevitable moments of banter with the bank president. Mr. Bray's only obsession -- other than getting through every day -- is an adolescent friendship with someone named Bill Jewitt.

Again, the type is familiar: "Bill Jewitt could as easily have chosen to persecute Mr. Bray as to take him under his wing, and there was an element in his friendship that never allowed Mr. Bray to forget this." Their companionship the summer after high school consisted entirely of lewd and fantastic talk about women and of drinking to excess, but Mr. Bray remembers it as a mystical period, "an eternity, a center of time . . . a main light by which Mr. Bray saw everything that had gone before and everything that came after."

Bill Jewitt goes on to lose his legs in a helicopter accident in Vietnam; when Mr. Bray goes to see him in the hospital, he finds a muted, pathetic ghost of his former friend. The spectacle disorients him profundly: "All the physical laws to which he was normally subject had been reversed." He can never bring himself to see Bill Jewitt again.

It is not hard to spot, in Upchurch's spare and remarkably acute sketches of the jamboree, a central concern with war, and the way its memory and specter washes over generations and spills into civilian life. The jamboree itself is nothing it not a paramilitary exercise, and in this instance it is conducted hard by a military base at Sandy Hook, exposed to the thunder of jet fighters doing their own war dance overhead.

There are fainter echoes of war everywhere in Jamboree: recollections of silly schoolroom drills to prepare for nuclear attack; the exploration of an abandoned World War II bunker at the campsite that ends in an accident no one can explain; one scout's drunken spree and subsequent encounter with a discharged soldier on a nearby beach; and the haunting comment of Ian Davies' mother as she remembered Britain's experience during World War II. "Nothing's felt quite so right as how we all acted together then," she says, "nothing since then has been quite so easy to understand . . . as the war was."

It is a credit to Upchurch that this theme is threaded through the narrative unobtrusively, although it is a pity that his own convictions remain, if anything, too unobtrusive. Quite evidently, he has a lot on his mind -- not just about war, but about the American character, which invests its faith "not so much in the actual weave of a moral fabric as in the starch which kept the fabric stiff, inpliable, and, ultimately, unworkable."

Such patronizing asides occasionally get the better of Upchurch's story. By and large, however, he writes judiciously, vesting every sentence with all the substantive and syntactical freight it can carry. By holding a slender story to a proportionate size, Upchurch leaves a large impression and a most favorable one.