The following version of this book was used to create the guide: Morris, Heather. Three Sisters. St. Martin's Press, 2021.

Heather Morris's novel, Three Sisters, written from a third person limited point of view, follows the lives of Cibi, Magda, and Livi as they face persecution and imprisonment under Nazi occupation in World War II. At the outset of the narrative, when the sisters are young girls, they make a promise to each other, and their father, that they will stay together. After the Hlinka Guard comes to take Livi to a labor camp, Cibi decides to uphold their childhood pact and volunteers to accompany her. When the eldest and youngest sister are taken from Vranov, their childhood town, Magda is in the hospital and avoids being transported. She is wracked with guilt for not being with her sisters, but Cibi and Livi are both relieved that at least one sister has avoided imprisonment.

When Cibi and Livi are finally released from the cattle cars, they are forced into Auschwitz-Birkenau. The sisters are stripped of their possessions, hair, and dignity by SS officers and forced to live in a flea infested barrack. Over the course of years, Cibi and Livi struggle to survive the inhuman environment; they use their promise, to stay together, as a reason to persevere in the face of brutality. Cibi helps Livi recover from typhus by smuggling an onion into the barracks and Livi’s presence reminds Cibi that she must stay alive to protect her sister. While the eldest and youngest sister are imprisoned at Auschwitz-Birkenau, Magda lives in hiding in Vranov. Every Friday on Shabbat, she hides in the neighbor’s crawl space or the forest to avoid the Hlinka Guard. While she is weary of slinking around her own home, Magda knows that she is lucky to still be in Vranov. Her ability to escape the concentration camps instills her sisters with hope and gives them the courage to survive.

Later on, Magda, her mother and grandfather, resign themselves to the fact that they will no longer be able to hide from the Nazis. They report for transportation and are taken to a school. Magda, however, is separated from her family members and transported to Birkenau. A fellow prisoner informs Cibi that she saw Magda exiting the train and the eldest sister smuggles Magda into the barrack that she and Livi occupy, at the concentration camp. Magda helps Livi and Cibi remember their life in Slovakia and uses memories to fortify her sisters with hope for a life after Auschwitz. When the sisters are forced into the death march they decide to run away after noticing that the SS officers are abandoning their posts. Together, with a group of other women, they flee into the woods and stay at an abandoned mansion in Germany where they take time to regain their physical strength.

After the war, Cibi, Magda, and Livi move to Bratislava, the capitol of Slovakia. They commune with other survivors and start to build a new life. Cibi gets married and has a baby. After years in the capitol, Livi decides that she wants to move to Israel to escape the lingering antisemitic sentiment in Bratislava. She and Magda join the Hachshara, travel to Haifa, and start a new life while they wait for their eldest sister to join them. In Israel, the sisters learn to live boldly and unabashedly, they recover from their trauma by building new lives, finding love, and having children. At the end of the novel, the sisters no longer need to verbally renew their promise to stay together, they know that no matter what happens in their lives, or where they are, their sisterhood will always give them the courage to persevere.