A Holocaust story as fascinating and compelling as it is terrifying and puzzling — a book about aging and war crimes, pain, and pride.

In the middle of summer, omnipresent heat radiates as a group of elderly people are remembering their youth. The story focuses on two sisters, Leokadia and Czechna, who live together in a retirement home not far from Warsaw. These are not ordinary stories they are sharing, because both of them spent time as children in a concentration camp in Nazi Germany. At the center is Czechna, who at the age of 12 was saved from extermination by the notorious doctor Josef Mengele, the real-life Nazi officer and physician who was known as the “angel of death” for the experiments he conducted on prisoners, including twins and siblings.

This is a story both provocative and disturbing about the fear that lingers in victims. Was the sisters’ relationship with the executioner a desperate attempt to save their lives, or perhaps they harbor a hideous pride and sense of superiority over other prisoners? Rudzka’s extraordinary writing turns unsettling questions about memory and survival into art.