Since I haven't read 'The Return' by Edith Tiempo, it's hard to say exactly. However, many works of literature deal with common themes such as love, identity, and the passage of time. It's possible that this story also explores these or related themes. For example, if the story is about a character returning to a place, themes of memory and change might be present. Or if there are relationships between characters, themes of loyalty and betrayal could be involved.
I'm not sure specifically as I haven't read it. It could be about the city of Memphis, perhaps with a story set there involving the local culture, people, and their lives.
Memphis Belle is indeed rooted in truth. Although some elements might have been dramatized for the screen, the core events and characters have a basis in real history.