A daughter’s powerful journey into her mother’s greatest secret—and the war that split her life in two.

From June 1940 to October 1943, the young German-Jewish refugee Ernst Cosmann, known to his friends as Erco, wrote 109 letters from his home in the Netherlands—and later from the Dutch transit camp Westerbork—to his fiancée, Ilse Birnbaum, who had fled with her parents from Berlin to Amsterdam. But whereas Ilse survived with the underground Joop Westerweel resistance group, Erco did not share her fate. On September 14, 1943, Erco was finally transported to Auschwitz. In his last letter before his departure, he wrote Ilse: “Stay strong, believe in our love and our shared future.” He never returned.

More than seventy years after they were written, Ernst’s 109 letters are a testament to the resilience of love in the face of unimaginable loss. In The Last Letter Before Auschwitz, Ilse Birnbaum’s daughter, Haya, unravels her mother’s lifelong secret—her life in the resistance, her first love, and the incredible loss she endured.

Weaving together Ilse and Ernst’s heartbreaking story with the historical context of Jewish life in the Netherlands, Haya Ravinsky-Mandelbaum paints a haunting picture of life before and after the war and brings to light the incredible hopefulness of its members in an often-overlooked part of World War II.