The prodigiously gifted Elizabeth Swados -- author, composer and director of that remarkable musical production "Runaways"--now turns her hand to fiction. The results are mixed, as is invariably the case with first novels, but, on balance, most agreeably energetic and appealing. "Leah and Lazar" is a contemporary fable about a young woman's search for identity, a familiar subject that Swados manages to treat with a distinctively fanciful touch.

Leah and Lazar are sister and brother, 9 and 14 years old, respectively. They live in upstate New York with their parents; the time is the late 1950s. Their father is an industrialist, a handsome man--"He had dark curly hair, peppered with gray, a finely cut mustache--he was tall and thin and walked very straight, because posture, he told Leah , had a great deal to do with the image one projected"--whose affectionate instincts are smothered under a blanket of businesslike reserve and diffidence. Their mother, by contrast, is a wispy, elusive figure who flits in and out of their lives without ever making a solid, lasting impression.

The result is that the children are left pretty much to themselves. Lazar, when we first meet him, is a delight, a wildly eccentric boy who is the light of his sister's life:

"She tried to keep her wild, unruly head of hair organized for his inspection. She tried to get the sleep from out of the corners of her wide, gray eyes. Lazar told her she was as beautiful as a mad Polish princess. He himself was often grubby, with his white socks and their black toes. His fingernails were dirty and his neck had lines of black on it as if he'd rubbed himself with newsprint. He was tall and skinny with thick glasses and crossed eyes. He moved nervously as if always impatient. Yet he was handsome in a proud, furious way. He brought Leah books to read, suggested outfits for her, and now and then gave her a short hug and a smacking kiss."

But Lazar's gaiety and whimsy are merely his thin lines of defense against the insanity that burns within him. It surfaces most ominously when he goes off to college. There he finds himself rooming with one Arnold J. Saks, "a street boy from New York City" whom Lazar, in a fit of late-adolescent infatuation, decides to adopt as a mentor. Unfortunately for him, that means instruction not merely in the fine art of being hip, but also in the consumption of various damaging drugs. While the charismatic Saks goes blithely about his own way, the discarded Lazar is sent off to a mental hospital--a step that marks the beginning of the end of his bright, sad life.

This leaves Leah very much on her own, and very much too young to know how to cope. A fascination with a fellow named Artie leads her to run off with him to Florida, where she earns him two grand a week as a child prostitute; here the novel is sharply reminiscent of "Runaways" and its two powerful songs, "Minnesota Strip" and "Song of a Child Prostitute." At the end of this experience she is only 14 years old, world-weary yet still possessing "some molecules of a child in her." She sees herself as "full of disguises and identities," with her real self still undiscovered. She talks with an admissions officer at Bennington, who listens to a somewhat embellished account of her sordid young life and offers this observation:

"I think you're tired. I think you want a vacation. You want to lie around in the mountain air, read books, think about yourself, go to boring Williams mixers and be told irrelevant facts by outdated old professors. You want to be a regular girl."

So off to Bennington she goes. But her tour of the seamier sides of contemporary experience is far from over. Ahead of her lie, among other things, various exposures to radical and pseudo-radical politics, an introduction to show business, an abortion and a terrible loss within her family. But at the end she emerges as a strong, independent girl who stands on the threshold of womanhood. She has rejected Lazar's self-destructiveness in favor of her own dignity and self-awareness. However painfully won, hers is indisputably a victory.

As the above suggests, a major weakness of the novel is Swados' insistence on plunging Leah into virtually every nook and cranny of late-20th-century life, no matter how sordid or bizarre. Too often she stretches credulity right past the breaking point, and she has difficulty restoring it--a problem that is compounded by her troubles with chronology, such as anachronisms (the Beatles before their time, among others) that pop up with annoying frequency. But these difficulties are largely canceled out by the novel's ingratiating combination of tenderness and insouciance, precisely the same combination that was so crucial to the success of "Runaways." Elizabeth Swados is obviously a person of great humanity and humor; these are the distinguishing qualities of her first novel, just as they have been of her work in the theater and popular music.