Siege Perilous in the Court of Dutch Schultz : BILLY BATHGATE <i> by E. L. Doctorow (Random House: $19.95; 320 pp.) </i>

Aking is known by the tone of his retinue. E. L. Doctorow elevates the story of the gangster, Dutch Schultz, into a cycle of rise, fall and renewal by using the lofty voice of a prodigious 15-year-old apprentice-boy.

Like virtually all of Doctorow’s work, “Billy Bathgate” uses some of the features of a period piece to do something quite different. Here, the period is the 1930s, when Schultz flourished in his own ferocious fashion until state prosecutors--notably, the late Thomas E. Dewey--began pressing him hard, and a rival gang rubbed him out.

Doctorow’s novel makes full and loving use of the manners, the artifacts, the savors and the rhythms of the ‘30s. He is marvelously skillful at getting into the thoughts and the lingo of the time.

But that is not all. There is also a contemporary sensibility at work at some mid-point between the author and his narrator. The Billy Bathgate of the title, the 1930s apprentice, recalls his story today, in the 1980s.

It is, as “Ragtime,” “Loon Lake,” “World’s Fair” were, a dialogue between two eras. And Doctorow’s ultimate purpose, aside from entertaining and enthralling--which perhaps he has never done so well as here--is only apparently to re-create the past through this dialogue. In fact, it is to give an edge, an unsettling undertone to the present.

Billy is an apocryphal figure amid a lot of real, or only partly embroidered New York history. The Schultz that Billy remembers--his idol, his mentor and, in the way symbolic fathers are, his victim--is both real and transfigured. It is the difference between a 6th-Century Welsh chieftain and the myth-enshrouded King Arthur of Thomas Malory.

The Arthurian comparison goes further. Billy is a Bronx slum-kid who catches Shultz’s eye. He is a protege but in a distant, mysterious fashion. Like some Arthurian Round-Tabler, he is sent on a quest, marked by lethal puzzles and ordeals. In this case, the object is not the Grail, but a seat at the gangster-king’s right hand.

Billy becomes an errand boy at numbers-racket headquarters. As an initiation, he is taken to watch the arranged death--by apparent mishap--of a troublesome window washer in a union that Shultz controls.

Billy is tutored in detail by Schultz’s accountant, Abbadabba Berman, a cripple and a mathematical genius. Schultz himself is alternately remote and close, benevolent and threatening. Billy never knows when he is in favor and when he may be liquidated.

It is the truest apprenticeship. Schultz’s own life of perpetual combat and deadly gambles is mirrored in Billy’s uncertainty about his position, and even his life.

He becomes a busboy-cum-informer in a Schultz-controlled bar. He witnesses Schultz’s personal liquidation of a lieutenant suspected of treachery. He is a kind of chaperon and companion to the gangster’s high-society mistress, and briefly--though he is only 15--her lover.

Still 15, and still wearing short pants, he is assigned to shadow Dewey. Schultz, unhinged by the net closing about his operations, wants to kill the prosecutor. And Billy is there, in a New Jersey restaurant, when the Mafia chieftain, Lucky Luciano--fearful that such a scheme will ruin them all--has his men kill Schultz and his lieutenants.

Billy tells the story in a series of scenes, and what vividly cinematic scenes they are! He begins on a tugboat chugging off New York Harbor late at night. Schultz has kidnaped his lieutenant, Bo Weinberg, suspecting him of dealing with his rivals.

We see Bo, tied to a chair and having his pants legs rolled up by Irving, Schultz’s meticulous assistant. Here, for a specimen of the book’s brilliantly precise language, is Billy’s description of this quiet technician:

“He was a professional, but since he had no profession other than dealing with contingencies of his chosen life, he carried himself as if life was a profession just as, I suppose in a more conventional employment, a butler would.”

Pants rolled up, feet white and naked, Bo is about to take Irving’s arm and be helped into a tub of wet concrete. When it hardens, Schultz will come up--he has taken Bo’s girlfriend to a cabin below--and kick Bo overboard.

Shod in concrete, his tuxedo rumpled, Bo remains elegant nonetheless. Schultz, on the other hand, is awkward and ill-clad despite the expensive clothes he keeps tugging at. “He tried constantly,” Billy tells us, “to correct his relation to his clothing.”

Other scenes are related with a similar mix of rich detail, irony, tension, and a nervy, darting reflectiveness that keeps taking us in unexpected directions.

There is Billy’s first encounter with Schultz--he is juggling bottles on the sidewalk--and his hilarious stratagem for getting taken on as a messenger boy. There is a whole pastoral-comic sequence in an Upstate New York town where Schultz and his henchmen settle down for a few months. Their task is to spend money and play the role of good citizens--Billy has to go to Sunday School--so as to impress the local jury empaneled to try them.

Billy’s voice is by turns flowery, baroque, mystical and down-to-earth. It is mannered talk, yet supple enough to accommodate both the questing 15-year-old, as recalled by his older self; and Doctorow’s own vision.

After Schultz is gunned down in the New Jersey bar, Billy slips away, unnoticed. He has the combination to his master’s safe, and clues to where the rest of his fortune is stashed. Later, he tells us, he will use the money to build up his own empire.

He does not tell us who he has become, nor whether he is still connected to the gangs. It does not matter, he implies. Gangs and “legitimate” enterprises come and go; the money is unchanging and immortal.

So much for the dark thread that runs--as it did in “Ragtime”--through a gaudy and elegant book. It is a binding thread, a governing one.

And there, perhaps, is the underlying weakness of “Billy” despite its beguilement. As in his other recent books, Doctorow governs his work as a craftsman governs his material. The pulse and pattern his characters move to seem implanted; he has given them a life-like mechanism, not life itself.

At his best, that is, his novels are prodigious toys. When they end--even his placement in a past time makes their endings seem like an off-switch--the thread is in his hand. The toy goes back to him. We open our eyes just where we have closed them. Like Bo Weinberg, though infinitely more agreeably, we have been not on a journey but a ride.