Alan Saperstein's second novel, "Camp," calls up an image: an early summer morning in a glade surrounded by old heavy trees; an arrow flies across the glade, glinting in the sun, bores into one of the old trees, shivers for a second and is still; nothing else happens. This novel is that quick and savage, that mysteriously menacing and dreamlike. It is a horror story told around a campfire, a nightmare spinning together obsession, demented power and the violation of innocence. In one of its scenes a melancholy little boy who is given to seizures, the stuttering son of a poet, saws off with a stone and with "innocent intensity" the head of a sparrow to see what makes it sing. The entire novel does something like the same thing, and does it so graphically that it will very likely haunt you for some time after you have finished reading.

Saperstein, whose first novel, "Mom Kills Kids and Self," was widely praised, is a wonderfully vivid writer. If in his efforts to bring words to the eye he is capable of occasional sentences as ungainly as, "Like locomotive smoke and track clacks, Geoff Thomason let out a chain of chest rales and shallow breaths in ironic counterpoint to his inch by inch maneuvering toward the examination room," he is also capable of ones precise and luminous with meaning: "It was an image that never changed, not even in the smallest detail, and yet it had no detail. It was indescribable; it just was, the way one's image of school just is, or of army life, or of the business world, or a stay in a hospital, or of traveling abroad, marriage, old age, death, all images that time and instinct have printed onto our brains in braille, images we feel rather than see."

The particular image being discussed here is the archetypal one of a summer camp where secure, sturdy children play and study nature and sing and hike and dance and swim in a fresh, healthy environment, and that image is articulated by alluring prose and photographs in a brochure prepared by the Geoff Thomason mentioned above. When Thomason was 14 months old his parents abandoned him in his high chair, accidentally, for three days to go on a belated honeymoon. Out of hunger and thirst, Thomason ate his own thumb and he never got over it. His mentor and healer is a towering, rock-hard chiropractor named Dr. Stone who has genius in his hands and a deranged mission to adjust the spine of the entire world.

Stone and Thomason co-found Camp Freedom and attract to it a small group of variously abandoned little boys, none of them secure or sturdy, and two counselors, Francis and Frances, who learn on their arrival there that the real Camp Freedom does not correspond very well to Thomason's image. In the New Jersey Pine Barrens, the place has no playing fields or tennis courts, no theater or science lab or bridle paths, not even running water or toilets or electricity, but only a small collection of collapsing cabins, a leech-filled stream and a scabby clearing.

It becomes apparent, irrevocably and immediately, as things do in a dream, to the boys, to Frances and Francis, to a number of other young counselors who show up later, and to Gus, a boozy old local who is captured and forced by Stone to serve as the camp cook (the novel's sometimes narrator), that they are caught here--pinned like so many butterflies to Camp Freedom by Stone's obsessions. We are told that there is no cruel ambition, no secret depravity to be found in the characters of Stone and Thomason, "Only the relentless desire of the one to save the world and of the other to spread the gospel. And that," observes old Gus, "was even more terrifying than pure and simple malevolence."

In his efforts to purge the campers of physical and mental illness, Stone regularly and painfully adjusts their small backs on a rack-like chrome table; he dangles them over the leech-infested stream; he threatens to throw them into ditches full of their own waste. Incidents of horror, stark as raisins stuck into the dough of the commonplace, begin to multiply. The sparrow is murdered, as are two local dwarfs who have a grudge against the camp. One boy disappears, another goes catatonic, and another permanently sleepless in trying not to wet his bed. A parent, then a policeman "without jurisdiction," more parents, and finally a television news team, come and go, again as in a nightmare, with no power to help, no power to change the landscape of the nightmare or to alter its course--a course which brings both Camp Freedom and "Camp," finally, to a truly chilling end.

Just before he escapes that end, Gus, the bewigged, grizzled, humane narrator, tells a story to the campers around a campfire, a story that serves as a little paradigm for the novel. Before he begins it, one of the boys asks if the story is scary.

"All stories are scary," says Gus.

"Camp" is a story and it is very scary, but it is also very skillfully written and completely gripping, and all of us need to be scared from time to time.