original: While it is a self-contained story, the book continues and develops many of the themes touched on in the first book.
simplifications: It is its own story, but the book grows many of the topics in the first book This independent book keeps developing many of the themes from the first book. While a self-contained story, the book develops many of the themes in the first book. The book wasn't a sequel. The story does develop the previous book. It also copies themes. While it is an independent story, the book develops many of the themes from the first book. While it has its own story, the book goes on and develops many of the themes of the first book. The book continues many of the themes that appeared in the first book. Even though it is its own story, it talks about many themes discussed in the first book. It is a self-contained story. However, the book continues and develops many of the themes touched on in the first book. While this is a self-contained story, the book remains and develops most of the themes touched upon by the first book.