Into the Night Sky : The tale of a modern-day Huck Finn : RULE OF THE BONE, <i> By Russell Banks (HarperCollins: $22; 390 pp.)</i>

Trying to tell the story of a modern Huckleberry Finn, with present-day counterparts for Jim, Tom Sawyer, the raft and other situations and characters as well, Russell Banks takes some awful risks. Several he manages admirably, several he flunks, and the largest he ignores at his peril.

“Persons attempting to find a moral in it will be banished,” Mark Twain wrote at the start of his masterpiece. It’s not that Huck’s and Jim’s story lacks sharp observations upon the oddities and horrors of life in the South before the Civil War. Of course it has morals; but for us to be free to sense Huck’s own buoyant and picaresque freedom, it is necessary that we are instructed not to look for them. The morals arise imperceptibly from the adventures; they are in Huck’s learning, not in his preaching. And when he does attempt a moral, instead of dropping from his lips it curls upward along with the smoke from his corncob.

Banks’ Chappie, a 14-year-old Upstate New Yorker, runs away from his abusive stepfather, takes refuge with his wise-guy buddy Russ and a posse of bikers, escapes from a fire but is thought dead, shares a bucolic life with an old Rastafarian in a burned-out bus--a raft, of sorts--and ends up as the old man’s disciple in some seriously awful schemes in Jamaica. He uses a Huck Finn-like first person to recount his adventures and speculate about them. The book’s first paragraph, in fact, is an ingenious variation in contemporary youngster-talk upon Huck’s own prefatory apologia.

Like Huck, Chappie is an innocent despite his scabrous present-day version of 19th-Century youthful rascality (smoking pot instead of tobacco, and dealing it as well; stealing hundreds of dollars at a time instead of “borrowing” this and that; having sex with a woman as a way of getting back at her villainous lover). The difference is that he keeps telling us so. His high-mindedness is not something we notice but something he draws our attention to. He is staunchly for the outcasts--his Rastafarian mentor, an abused and abandoned little girl, a violent but decent biker--but his partisanship has an insinuating quality that seems to hustle us into uplift.

Author of the powerful “Continental Drift” and the even better “The Sweet Hereafter,” Banks writes some excellent individual scenes in “Rule of the Bone.” There is the artfully managed sick horror when Chappie, still partly a child, comes home after his adventures with the bikers, the fire and a free-and-easy few weeks with Russ (his Tom Sawyer) in a boarded-up summer house. Perhaps he can stay; his stepfather, though drunk, greets him affectionately. Then he tries to sodomize him.

There is Chappie’s convalescence afterward in the burnt-out school bus--the same one whose fatal wreck provides the devastation in “The Sweet Hereafter”--where I-man, the Rastafarian, squats. A former migrant worker from Jamaica, I-man cultivates a vegetable garden liberally planted in ganja, cooks Jamaican stews, keeps his Rastafarian observances, and gradually heals the stricken Chappie with his example of tenderness and anarchic independence.

Eventually I-man (his patois, beautifully rendered, uses “I” and shuns “me”) decides to return to Jamaica. “Up to you, Bone,” he replies when Chappie--who has renamed himself after having two crossed bones tattooed on his arm--wonders whether to go too. It is a guru’s mantra; a phrase that leads the boy through the ordeals he will encounter.

In Jamaica he works in a Rastafarian commune where I-man has legendary status as a former companion of the late Bob Marley and other big Rastas. The main activity, of which I-man takes businesslike charge, is growing, processing and distributing kilo bricks of ganja. Some goes to tourists in Montego Bay; most is loaded onto planes owned by a white drug syndicate and flown to the United States.

One member of the syndicate, it turns out, is Bone’s real father, who had run off to Jamaica years before, set up as a doctor and moved in with Evening Star. A blonde, ex-hippie heiress, she lives in a hilltop mansion where she gives nonstop parties, lavish with drink, drugs and sex, for American women past their prime but not their purses, and handsome Jamaican studs.

Bone is welcomed affectionately; for a while he thinks he may be able to get off the “raft,” his picaresque life with I-man. But just as the strait-laced “civilizing” of Tom’s kindly Aunt Polly was too much for Huck, the degenerate civilizing of the differently kindly Evening Star is too much for Bone. And when I-man is murdered by the syndicate over a payment dispute--white society is as lethal to him as it was to Jim, the ex-slave--Bone lights out for the territory.

Well, not quite; and the difference marks the degree to which Banks miscalculates his contemporary Huckleberry Finn. Instead of Huck’s laconic lighting-out phrase, Bone delivers a lush farewell. Aboard the boat on which he works passage out to his future, he looks up at the night sky. He makes up his own constellations: one for I-man; one for his biker friend who died searching the burning building where he thought Bone was trapped; and one for the abused child whom Bone stole from her abuser.

“For the rest of my life,” he says, “no matter where on the planet earth I went and no matter how scared or confused I got, I could wait until dark and look up into the night sky and see my three friends again and my heart would swell with love of them and make me strong and clear-headed.”

It takes a voice to make a fictional character. It takes a very special and hard-to-achieve voice to make a first-person fictional character. And it takes something close to a miracle to achieve a first-person voice for a 14-year-old that will do vital and nuanced justice not only to the boy but to the age-old world he moves through. Bone’s voice performs excellently, and the story it tells is varied and interesting for the most part, and sometimes more than that. But it is essentially a performance; one that flattens out, summoning applause more than it arouses it.