I think Hannah is gonna go back in time and get captured by Nazis because it says on the back page that She goes back to 1942 and then she opened the door to Nazi soldiers.
The cover leads me to think that she runs into a warrior and she has to get pulled into a holocaust concentration camp.
In the book, hannah wrote numbers on her arm like a concentration camp tattoo and showed it to grandpa will and she is mad at him because he yelled at her.
The Devils Arithmetic
on the back cover it says as she opens the door open to prophet Elijah, she is swept back in time to 1942, to a polish village where anyone calls her Chaya.
going back in time to when the nazis were real
The text leads me to think they are a Jewish family because the celebrate Seder which is a Jewish holiday of remembrance. Also what helps me know that they are Jewish is that grandpa will has his concentration camp number tattoo.