In the book "The Devil's Arithmetic" Hannah is at her house contemplating that she dreads the events of the evening. She joins her family and they begin the prayers. Hannah is supposed to go and open the door to let in the prophet "Elijah" when she is suddenly finds her self in a small village in another country. The people tell her she has been sick and reintroduce them to her.
Hannah is confused but tries to figure out where she is and what is going on. She learns her parents are dead and that she lives with relatives. Hannah and her relatives are going to attend a wedding. As they approach the synagogue they see military trucks. The trucks won't allow them into the church. Hannah suddenly realizes that they are Nazi's and they are going to take them to concentration camps.
Everyone is used to her odd stories so no one believes her. They are taken from the trucks and put onto a train where they disembark at a concentration camp. Hannah and her cousins are separated from her aunt.
Hannah meets Eva, who will later be Aunt Eva in the food line. She tells her about her everything bowl and teaches her how to survive the camps. She also tells her about the doors to a cave where it is dark and people don't come back out.
The children are forced to work hard and Eva becomes weaker. Eva and Hannah's cousins are chosen to go to the big doors whether she knows they will die. Hannah take's Eva's kerchief and switches palaces with her. As the doors close to the death chamber Hannah turns and sees her family.
Hannah has returned to the modern century. She sits in the seat that is kept for Elijah. She talks with her aunt Eva and learns that she is the girl whom Hannah had switched places with and that Hannah was named after the original Eva who had died in the concentration camp saving her aunt.