THE ZIGZAG KID.<i> By David Grossman</i> .<i> Translated from the Hebrew by Betsy Rosenberg</i> . <i> Farrar, Straus & Giroux: 308 pp., $24</i>

The circus train starts to pull out, loaded with clowns, trapeze fliers and educated bears. The coupling fails. The locomotive puffs and hoots through the countryside. The circus sticks in the station.

Israeli writer David Grossman has packed comedy, fantasy and moral instruction into his tale of a boy on a quest. Grossman labors to hitch up his gaudy display and get it moving. There is a great deal of movement, in fact, but most of it is the author’s.

The extravagant adventures of Nonny Feuerberg, the Zigzag Kid of the title, take place on the eve of his 13th birthday and bar mitzvah. Like Lewis Carroll’s Alice, Mark Twain’s Huck and Salinger’s Holden Caulfield, Nonny is a journeyer whose picaresque travels are an anarchic interrogation of the world he is on the verge of growing into.

Huck, Holden and Alice, the great child questers, are memorable not merely for the quality of their adventures--external, internal and phantasmagoric, respectively--but by their vivid and indelible characters. They are autonomous--their three eccentric authors disappear into them--and though they are bossy and instructive, we feel it is they, not the authors, who are bossing and instructing.

Nonny, a fey insurgent, has comments and history but not much character. He is led by his author’s hand and performs his author’s business. It is honorable business, but Grossman, who has written two brilliant books about his country’s treatment of its Arabs and a powerful novel about the Holocaust, is too protective of his young protagonist.

Peril is cushioned by safety in Nonny’s adventures--not the best recipe for the picaresque. The adventures dangle from an umbilical cord. The grown-ups have instructively arranged them.

Nonny, hair-triggered and voluble, lives in Jerusalem with his father, a star detective undermined by nerves. His mother, Zohara, disappeared and died when he was little. Gaby, his father’s secretary and longtime mistress, cherishes Nonny and recognizes the anguish of a child with a missing part. Police mascot and his father’s would-be disciple, Nonny struggles with a wildness he can’t identify. It comes from his mother.

Gaby defends Nonny when teachers complain of his conduct. Some kids, she tells them, are triangular and don’t fit the school’s square patterns. Others are circles. Nonny is a “zigzag kid.” That is apt. But it is too apt. It is an author’s oar steering Huck Finn’s raft. It is the moral against which Mark Twain threatened death by shooting.

Gaby persuades the father to organize a magical mystery tour for his restless son. Equipped with a letter of instructions, Nonny is put on the train to Tel Aviv for a series of planned surprises.

The first comes when a policeman enters his compartment handcuffed to a prisoner. The policeman falls asleep, the prisoner steals his key, releases himself, dons the policeman’s uniform, dresses the policeman, still sleeping, in his own clothes and reattaches the handcuffs. Now he is the policeman, the other man the prisoner.

The blurring of cop and crook is the key to everything that follows, as is the password in Nonny’s letter. A passenger will identify himself in some fashion; Nonny is to introduce himself with the phrase “Who am I?” The story provides the answer.

He will be handed on, so the arrangement goes, to a succession of passengers, each of whom will conduct him on an adventure. But the plan is intercepted. A charming old man in the next compartment smiles at him; when Nonny asks the code question, the old man introduces himself as Felix and takes over the game.

Felix leads Nonny to the locomotive. First Felix charms the surly driver; then he pulls a pistol and forces him to halt the train in the middle of a field. Smashing the train’s two-way radio, he takes Nonny to a vintage black-and-yellow Bugatti limousine hidden in the trees. He arranged for it, he explains, through a friend in a car museum.

Nonny is bewildered, excited and angry. They have committed a crime, he protests. Not really, Felix says; his pistol was a toy, and to prove it he pulls the trigger. It goes off. The toy store clearly made a mistake, he insists blandly, but offers to take Nonny home if he wishes. Through everything that follows, Nonny is torn. He is the son of a policeman and of a mother whose wild charm and wilder life Felix gradually reveals to him.

Meanwhile, they are fugitives. Filling his wallet with sand, Felix takes Nonny to a luxurious restaurant, eats and drinks hugely, asks the waiter to hold his wallet while he starts his car and drives off. They disguise themselves: Felix as a much older man, Nonny as a girl. When a policeman stops them to ask if they’ve seen the fugitives, Felix steals his wristwatch. “My fingers think faster than I can,” he explains apologetically.

Charmed and expostulating, Nonny is taken on more extravagant errands. At one point Felix steals a bulldozer to level a mountain of sand that is blocking the sea view from the apartment of Lola, an aging singer to whom he is mysteriously close. Nonny now finds himself whizzing through Israel on a motorcycle, with Lola riding sidecar. And bit by bit, the extravagant old couple tell him his mother’s story.

A free spirit, she rejected wealthy marriage offers to travel around the world as Felix’s partner in a series of spectacular thefts and swindles. She met Nonny’s father when he trapped her as she prepared to rob the diamond exchange. She fled into a neighboring chocolate factory, shot her pursuer in the shoulder, dived into a vat of chocolate and, when he dived in after her, rescued him because he couldn’t swim. After she got out of jail, he married her. They had a baby, Nonny, and then, unable to stand domesticity, she ran off and died soon after.

There is a great deal more. Some of it is entertaining, but it tries too hard and too extravagantly. Whimsy does the work of fantasy.

Increasingly, Nonny’s story takes on a dispiriting sentimental convergence. Long before his adventures and Felix’s explanations are finished, spontaneity has given way to management. It is a therapy story, in fact, tricked out as a quest: the healing of Nonny’s divisions by reconciling his inner cop with his inner outlaw.

There is a world of fictional difference between Alice beyond the looking-glass or Huck on the Mississippi and a summer at Outward Bound.