How does the author use foreshadowing in Rosaura a Las Diez?

In Chapter Three, Mrs. Milagros explains to the inspector that Rosaura's letters were not found among Camilo's possessions. This foreshadows Camilo's sudden disappearance..... the fact that he has fled or is possibly dead. Denevi leaves the reader to piece together the clues in order to discover what happened to him.