It's 1944 when the twin sisters arrive at Auschwitz with their mother & grandfather In their benighted new world Pearl & Stasha Zagorski take refuge in their identical natures comforting themselves with the private language & shared games of their childhood As part of the experimental population of twins known as Mengele's Zoo the girls experience privileges & horrors unknown to others & they find themselves changed stripped of the personalities they once shared their identities altered by the burdens of guilt & pain That winter at a concert orchestrated by Mengele Pearl disappears Stasha grieves for her twin but clings to the possibility that Pearl remains alive When the camp is liberated by the Red Army she & her companion Feliks
- a boy bent on vengeance for his own lost twin
- travel through Poland's devastation Undeterred by injury starvation or the chaos around them motivated by equal parts danger & hope they encounter hostile villagers Jewish resistance fighters & fellow refugees their quest enabled by the notion that Mengele may be captured & brought to justice within the ruins of the Warsaw Zoo As the young survivors discover what has become of the world they must try to imagine a future within it