SOME OF US are diehards. We never give up, never hear those prophets mouthing words of doom over the novel as we know it, telling us that plot and character are as anachronistic as the nickel newspaper and the ten-cent phone call. We approach a novel by a new, unknown writer with the anticipation and sense of adventure of a Columbus setting sail for the New World or a Neil Armstrong taking a giant leap onto the moon. And when we find a novel as beautifully written and perceptive as Uncle, we cry, like Archimedes in his bath, "Eureka!"

All of the above may sound extreme, but it is an extreme pleasure that a lover of good fiction gets from discovering a writer like Julia Markus. For Uncle, she received a Houghton Mifflin Literary Fellowship Award, a prize given at irregular intervals (the last one was awarded in 1974) to young writers of unusual talent. Previous winners have included Robert Penn Warren, Elizabeth Bishop and Philip Roth, to name only a few in a distinguished group, a company in which Markus holds her own. Uncle, in fact, announces a new, original voice in American fiction as surely as Goodbye, Columbus did for Roth.

Uncle is not, in fact Markus's first novel, La Mora was published by Decatur House Press, which Markus owns and operates with her husband here in Washington - but it is her first work which a large audience will have an opportunity to read, since small press books are not easily available. As such, it is likely to be compared to another first novel, Mary Gordon's Final Payments, which received favorable reviews earlier this year. Both are about self-sacrifice, specifically the sacrifices made by one family member for another, but Uncle is far and away the more intelligent and thoughtful in its recognition of the ambiguities and complexities of the motives and actions of its major characters.

Beginning Uncle, one hears in the first paragraph a strong voice that clearly sets this writer apart and wonders why it is that this ability to create a distinctive fictional voice seems to belong to so many contemporary Jewish writers - Roth, Malamud, Bellow, Singer, Paley, Apple, for example.

"One spring day," Markus begins, "Irv Bender gave up his chances in life for his younger brother. Irv was sixteen. He was standing at the top of the conrete staircase outside of Snyder High School. He made his decision from that height, looking down on the Boulevard and the monotonous rows of one-family houses across the street. On that spring day in Jersey City the sun had dissolved the clouds, and the remote sky appeared to be the color of aquamarine. The dust in the air was stirred by the breeze and the smell of something sweet could be discerned through the dust. Irv had his revelation. Fat, awkward, adolescent, he stood firmly at the height, while his spirit swooned and he gave himself away."

It is a situation familiar to readers of Yiddish tales, the story of one brother's sacrifice for another, a theme as old as literature itself. Yet there are no stereotypes here. Irv is no saint, and there are some darker motives subtly implied - his obsession with his younger brother, Babe, may be unconsciously homosexual, and his sacrifice may in part be the megalomaniac's desire to shape his world. Yet he is a good, decent man who loves intensely and takes care of his own. Babe is unworthy of Irv's sacrifice, but he is no villain; he is merely a weak, ineffectual man, doomed to failure, something he is honest enough to recognize very early. His suicide may be a coward's way out, or the only authentic act he's ever committed.

Irv prospers and buys a summer camp with his friend Mandy Merchheimer in the Poconos; eventually Camp Rose Lake will make him a rich man. He takes over the responsibility for Babe's widow, Esther, and daughter Suzanne. Mandy becomes a famous writer and leaves the running of the camp to Irv, who takes on an assistant, Larry Driscoll, a cold, calculating young man who is also Irv's lover and with whom Suzanne becomes involved. To each of these Irv offers affection and generous support, yet he exacts a certain price and each of them betrays him in one way or another. At the same time, Irv betrays each of them.

No one is good or evil, black or white, no one is just what he seems to be on the surface. Mandy is a charming and irresponsible womanizer yet he is not a cad, and the scene in which he seduces Suzanne is a model of loving initiation. Even Larry proves on his deathbed not to be as venal as one had thought. It is, one realizes, like life.

Perhaps the finest achievement of this short masterpiece is the reconciliation of the past that comes at the book's end. Suzanne, who has been estranged from Irv for years, goes to Florida to try to persuade her aging and ill uncle to go back home. The two of them, so alike in their fierce pride and determination, square off while Suzanne, now a well-known photographer, photographs her uncle for the first time. As they confront their mutual betrayals, they confront themselves, revising their perceptions about the past, acknowledging their strengths and weaknesses.

"'I am not what I started out to be,' he said in rage and shame."

"Her response surprised them. "I love you,' she said."

Julia Markus has written a remarkable novel about the power of love to redeem failure, our own and those of people we love. It deserves to be read.