The Devil's Arithmetic by Jane Yolen is a young adult (YA) novel that focuses on the mysterious time travel of a Jewish teenager from her modern life in New Rochelle, New York to war-torn Poland.
In the book, Hannah Stern is at her family's Passover Seder--a ritual feast that denotes the beginning of Passover and honors the liberation of Israelite slaves from the oppressive ruling of the Egyptian pharaohs. Despite the meaningful significance of these proceedings, she finds the traditions of her religion and lengthy stories of her family members boring.
When Hannah is asked to open the front door (a symbol of welcoming the prophet Elijah), she finds herself hurtled into a whole new life--that of Chaya Abramowicz, a Jewish girl in 1942 who has lost her parents to cholera and is now living with her aunt and uncle.
Hannah's eventually loses herself entirely in this new life, wholly absorbing her identity as Chaya. Hannah is eventually taken away by Nazi forces to a concentration camp (one similar to Auschwitz). Once there, she is put through all of the unbelievable tortures of the Holocaust. Hannah eventually sacrifices herself to save a friend's life and is killed in the camp's gas chamber.
This final act of bravery transports her back to her real life, where she now can understand the true suffering and triumphs of her Jewish heritage.