The following version of this book was used to create this study guide: Konar, Affinity. Mischling. Lee Bordreaux Books, 2016.

Twin sisters Pearl and Stasha Zamorski are 12 years old when they arrive on the station platform at Auschwitz with their mother and grandfather. They are swiftly placed into the care of Dr. Josef Mengele, the sinister Nazi who calls himself "Uncle Doctor" (12). Mengele runs an area of the camp known as “the Zoo” where he experiments upon anyone he perceives as different, including a brash albino, a family of little people, and numerous sets of twins and triplets (13).

Pearl and Stasha have a deep connection; they frequently read each others' minds and feel each others' pain, though the connection is frayed as their ordeal unfolds. Wise-cracking Stasha, who dreams of a future where her sister is a famous movie star, is given an injection that, Mengele claims, has made her immortal. Pearl does not know what she has been injected with, only that she is growing ever weaker and death seems likely. In addition to each other, Stasha has a friend named Feliks, a boy whose twin has died as a result of Mengele's experiments, and Pearl has a moment of romance with a resourceful messenger boy. Suddenly, their worlds are thrown further into chaos when Pearl disappears from an orchestral concert organized by Mengele.

Shattered by this loss, Stasha resorts to living in a sauerkraut barrel, inside of which she carves letters to her sister. When she is forced to emerge by Mengele's malevolent nurse to have her portrait painted, she is stunned to find her mother, whom she had not seen since their arrival at Auschwitz, is the artist. She learns that her grandfather is dead and she begins to plot Mengele's murder. A month passes while she awaits her opportunity. One day, he arrives in a car and tells her to get in. As they drive around the camp, Stasha sees her mother's body in the back of a truck. Her mission for vengeance takes on added urgency, particularly as she believes Pearl to be dead as well. Shortly after this, the camp erupts into anarchy. The Russians are at the gate, and the resistance movement within the camp clashes with the Nazis who have not yet fled. In the chaos, Feliks and Stasha witness the death of their friend Bruna, the albino teenager. They leave camp as part of the infamous “death march,” but they are left behind, lying in the snow.

Pearl, meanwhile, is not dead. She has been confined to a cage in one of Mengele's labs where she is discovered by the Russians. Though badly injured, Pearl flees Auschwitz with two of Mengele's staff who were prisoners themselves, the beautiful and tortured Dr. Miri and a kind former Czech Soldier the children call “Twins' Father.” They make their way to Krakow where the Red Cross steps in to organize an escape to Palestine. The transport is hijacked en route by Nazi soldiers and Pearl must flee.

Feliks and Stasha travel the war-torn countryside with Warsaw as their destination, as Feliks has told Stasha he believes this is where Mengele would hide out, and they have both sworn vengeance against him. On their journey, they are rescued from a murder attempt by heroic Jewish resistance leaders, explore the ruins of a museum, and barely escape an encounter with a group of Nazi deserters. When they arrive in Warsaw, Mengele is not there, and Feliks tells Stasha she is not immortal, Mengele told all of the children this same lie. Stasha plans to kill herself, but before she can, she runs into a man on the street who turns out to be her father, whom she thought dead. He had actually been captured by the Nazis as a member of the Jewish resistance and sent to Dachau. Her father has a newspaper with a photograph of Pearl on the cover. They try to find her through all of the relief organizations established for refugees, but have no luck.

Just as Stasha has begun to accept that she will never see her again, Pearl suddenly appears in Warsaw. They sit back-to-back and play a game they have always played in which they draw the same thing at the same time, using their twin telepathy. They commit themselves to remembering those they lost and learning to love the world again.