An author writes a story entitled O som da terra a tremer, and the story constantly entwines itself with his private life. The man lives alone and has an imaginary love story with a woman, Isabelle, who has a literary salon and always seems to be waiting for something. One day the two decide to go off together, or imagine that they have, but their departure never takes place. The novel the author is writing is about a sailor who, after spending many months at sea, finally comes to shore in a small city where he falls in love at first sight with a girl. Before casting off again, he gives the girl a book, but she is so sad she barely looks at it. Many years later, the book ends up in the hands of a professor who finds a letter from the sailor hidden inside it. It is a love letter, but the answer never arrived.