IN THE COURSE of a "long and rainy winter between wars," Yonatan Lifwhitz decides to leave his wife and his kibbutz, to leave Israel entirely. Before he leaves, he installs in his home a voluble, screwy, socially inept young man who has found his way to the kibbutz. Azariah, the newcomer, will take over Yonatan's wife, Rimona, and their dog. The kibbutz is scandalized. Yonatan's mother, Hava, is enraged. His father, the secretary of the kibbutz and a fierce old pioneer, is heartbroken. Azariah is delighted. Rimona is unmoved in her serenity. Her calm, in fact, represents the only peace to be found in this novel, and it is clearly symptomatic either of madness or retardation.

Rimona is certainly not the legendary omnipotent Israeli maiden. She is as white and delicate as a marble sylph, and as cold. She is, in fact, a heartbreaking caricature of femininity -- passive, accepting, accommodating, beautiful, and frigid, wanting nothing for herself. She simply reflects back what Yonatan tells her, in an insanely soothing litany. Her only drive is to promote peace, quiet, stillness. "Whoever has rested will listen," she says, making no more sense than usual. "Nothing untoward will happen if we keep still."

Only Azariah, the European refugee who stumbled into the kibbutz out of the rain, heeds her, and God knows he needs to: he's a social disaster, releasing avalanches of talk -- boasting, philosophizing, toadying -- a sort of Eastern European Jerry Lewis, literally falling over himself in his desperation to be accepted. Azariah makes the reader uneasy, as Oz means him to. We're constantly certain that he'll fail to live up to his boasts, that the kibbutzniks will reject him. Oddly enough, he always does what he says he can. Odder still, they do accept him, not only Rimona but Yonatan's father, and most touchingly, Yonatan himself. After fixing an engine, Azariah begins babbling to Yonatan about his triumphs and his enemies. We squirm, but Yonatan only thinks, "No two lonelinesses are ever alike."

For his part, Yonatan wants nothing more desperately than to be alone. Encircled as he has always been, he can't find himself. And because his father is larger than life, the boy knows he cannot be anything in that country until his father dies. "You dressed yourselves in rags," he thinks, "and ate dry bread with olives, and worked like coolies all day long, and sang yourselves hoarse every night, and lived in an ecstatic trance, and gave me a white, white room with a housemother in a white, white apron who fed me white, white cream to make me a clean, honest, hard-working Jewish boy with a soul of forged steel."

"You poor suffering heroes . . . you . . . maniacs . . . Your souls are seared into me like a branding iron, but I am not one of you."

It's the one thing Yolek, the father, never thought of. In him, Oz writes an elegaic portrait of the aging pioneers who fought to build the dream and now find that their children simply inhabit it, like any neighborhood they might have found themselves in. He doesn't understand Yonatan and can't hear him -- he becomes increasingly deaf as the book progresses -- and it breaks his heart that Yonatan runs away, perhaps to his American tycoon would-be father.

THIS IS Oz's strangest, riskiest and richest novel to date. He writes in his usual clean, blunt prose, his characters' voices ring true, and he creates a world which makes perfect sense, except that at its core is a series of impenetrable mysteries. Who, for example, is Yonatan's real father? It might be Yolek, or it might be Benya Trotsky, the radical- turned-Miami-tycoon, who lived on the kibbutz briefly and fell in love with Yonatan's mother, and who now wants to leave his empire to her son. Only the mother knows which it is, and she isn't telling.

For that matter, who is the father of the child Rimona gives birth to toward the end of the book, Yonatan or Azariah? Why does Yonatan provide his wife with a lover in the first place, and why does she simply accept the arrangement? Why is she so damned calm? And above all, what are we to make of Yonatan's brief and bizarre rebellion and his ultimate docile return?

In a novel with this many enigmas, with so many origins and destinations undefined and with key characters reacting in ways that seem otherworldly or mad, there is clearly allegory at work. That is usually the kiss of death for a novel -- and in fact, the heavy- handed allegorical twist at the end of Oz's Elsewhere, Perhaps (now reissued by Harcourt Brace) was disastrous to that book. But if it is the game that Oz is playing here, it's a fine and tricky one, right up to the end. If the old men's tug of war over their son is heavy with its allegorical burden, for example, the character of Yolek is not. The long letter he writes to his lifelong political enemy, Levi Eshkol, is as canny a portrait of bewildered old age and contentious pol as I know. Oz has spent craftsman's years developing a tender, ironic humor and an accuracy of voice that serve him brilliantly here.

It is only at the end of the book that the reader may begin -- the risk of Oz's game -- to feel that he's been led by the nose to Yonatan's epiphanic moment of terror, which makes little sense except as symbolic act, and the ensuing tableau of the young trio plus infant may be a bit contrived, but the end of this novel is almost a coda. It's the long and rainy winter of dissatisfaction, personal pain and slow growth that is its splendid core.

Rita Kashner is the author of "Bed Rest" and, recently, "To The Tenth Generation."