When the reader gets into her narrative, he finds himself in the year 1912, where the story begins.
These multiple perspectives give the readers more information about the characters regarding their feelings, thoughts, and motivations.
Mary Shelley uses three narrators in her complex narrative of Frankenstein to create a certain degree of objectivity- the novel starts with an epistolary structure with the letters of Robert to Margaret with include an account of the life of Victor and that of the narrative of the monster through the narrative of Victor.
It is a unifying tale within which one or more related stories appear.
For instance, in Homer’s Odyssey, Odysseus tells about his wandering experience in the court of King Alcinous, or his visit to the island of a sorcerer.