She flew alone into exile. Ever since the day in September 1973 when her uncle, Salvador Allende Gossens, Chile's Marxist president, died in a bloody military coup, she had lived in terror that she might be arrested. In the airplane headed for Caracas after the coup, Isabel Allende wept as she caught sight of the Cordillera, the snow-covered tips of the Andes, vanishing into the distance. Stepping off the plane in Venezuela, the wet green heat hit her in the face. "Those first days were terrible," she recalls. "I felt very lonely and desperate waiting for my husband to get out of Chile and thinking about all that I had lost. For a long time I felt like a Christmas tree that has no roots and will eventually die."

In fact, Allende, 42, has bloomed in exile. Her first novel, The House of the Spirits (Knopf, $17.95), was a major best-seller in Europe and South America in the last two years and has just been published in the U.S. The Book-of-the-Month Club has grabbed it; Allende's writing has been compared to that of Nobel prize-winning Gabriel García Márquez in his novel One Hundred Years of Solitude; and the reviews are glowing: "With this spectacular first novel, Isabel Allende becomes the first woman to join what has heretofore been an exclusive male club of Latin American novelists," said the New York Times.

She began The House of the Spirits in 1981, she explains, primarily as a letter to Augustín Llona, her beloved grandfather, who was then nearly 100 years old. He was the only member of her family who remained in Chile after the coup. "My grandfather thought people died only when you forgot them," Allende says. "I wanted to prove to him that I had forgotten nothing, that his spirit was going to live with us forever." In fact, the domineering central character of her book, Esteban Trueba, and his wife, Clara, are drawn from Allende's intense recollection of her own grandparents.

A sense of other worldliness pervades Allende's powerful, sometimes picaresque, sometimes mystical novel. Her family chronicle spans four generations of an eccentric clan living in an unnamed South American country. A beautiful woman with green hair is mysteriously poisoned; a human head is lost in the cellar for 20 years; a clairvoyant child ceases to speak; a young man breaks wind at a spring picnic and—humiliated by his loss of control—vanishes forever. A doomed Salvador Allende-like figure called "the President" makes a brief appearance. Throughout the novel Allende raises important questions about traditional macho Hispanic values, class violence and self-knowledge through social action.

Isabel Allende was born in 1942 in Lima, Peru, where her father, Tomas, served as a diplomat. Her parents divorced when she was 3, and she returned to Santiago, Chile with her mother, Panchita. There she lived in her grandparents' home. Her grandfather, she recalls, ruled his large tribe with a severe hand. Among other strictures, he banned radios, which he considered vulgar. But Isabel secretly listened to soap operas in the kitchen with the maid until one terrifying afternoon when her grandfather caught them in the act. "He came into the kitchen and destroyed the radio with his silver cane. Then he took me into his library and said: 'You shouldn't listen to other people's lives.' "

Allende was equally close to her grandmother Isabel, a spiritualist who held seances in her home. One day the grandmother reported getting a message from a spirit reporting that Spanish treasure was hidden under the living-room floorboards. The planks were pulled up but nothing was found. At the next seance, the spirit told her it had made a mistake.

In the midst of these strange occurences, young Isabel led a normal life at various private schools. She graduated at 16 and at 19 married engineer Miguel Frfas, her childhood sweetheart. Working as a secretary at a United Nations office in Santiago, she grew intrigued with the lives of the journalists she observed. Eventually Isabel became one herself and for many years had TV interview programs in the Chilean capital.

Over the years she remained close to her father's family and to her uncle Salvador, who was elected president in 1970. Three days before his death Isabel ate lunch with him. "Everybody was expecting a coup," Isabel says. "But my uncle said he would never leave La Moneda [the presidential palace] because the people had put him there and only the people could take him out and he would die there if it was necessary." (Whether he was assassinated or committed suicide has never been clarified.)

When the bombs fell on the palace, members of the family prepared to leave Chile. Isabel never summoned the courage to say goodbye to her grandfather. "Every day I would sit there in silence and try to find the words. He would say, 'Why do you remain quiet? What do you have to tell me?' The last day I kissed him. He would always say, 'Hasta manana, 'but for the first time in his life he said, 'Adios.' " He died six years later.

Today Isabel, her husband and their children, Paula, 21, and Nicolas, 18, live in an airy modern house in the hills above Caracas. Allende writes a weekly newspaper column on "anything I like" for El Nacional. (Recent topics have included Marc Chagall and her first impressions of the opera.) She is also at work on a novel. Another, about a young couple in love who trespass on the violent terrain of a dictatorship, was published last November in Spain, where it has become a best-seller. Knopf will publish the book in the U.S.

Long separated now from the country her Chilean compatriot Pablo Neruda once described as the "long petal of a flower," Allende has found a certain peace. Although she hopes to return some day, she no longer misses so acutely the house and belongings she was forced to leave behind. She is comforted, in some elusive way, by two of her grandmother's possessions: a mirror and the wax orange blossoms from her bridal wreath. "I feel happy in Venezuela," Allende says. "I no longer feel I am only Chilean. I care very much for my own continent. I am Latin American now."