Theme of Secrets from The Book Thief

As I almost finish reading The Book Thief  by Markus Zusak, I noticed near the beginning of the book that secrets has become a huge deal with the conflict in the book. For example throughout the book, it is being told in a narrator's point of view but there are hints given that it wasn't the main character Liesel Meminger. On page 349, the author writes, "I'll never forget the first day in Auschwitz, the first time in Mauthausen. At that second place, as time wore on, I also picked them up from the bottom of the great cliff, when their escapes fell awfully awry. There were broken bodies and dead, sweet hearts. Still, it was better than the gas." This shows that the author wouldn't be a German because some Germans who went against the Nazi would also be in the gas chamber with the Jews. So the narrator might be a type of spirit that appears a lot because there might be a lot of death 's involved in the book. I like how the author gives settle hints about the narrator throughout the book that would want to convince the reader to finish the book to see who was the narrator the whole. If you think your prediction is right about the narrator, find out in The Book Thief  by Markus Zusak.