Etty Hillesum began keeping a diary on March 9, 1941, at the request of her beloved. In it, the thoughts and emotions of a young woman living through wartime are captured.

After completing her law studies, Etty Hillesum started working as an administrative assistant for the Jewish Council in July 1942. This organization, under the orders of the German occupiers, governed the Jewish community. Hillesum eventually found herself compelled to work in Westerbork Camp. Due to her position, she had a special status that allowed her to move freely within the camp. Because of her role in the Jewish Council, she traveled back and forth between Amsterdam and Westerbork several times. Although she called Westerbork "hell," Etty Hillesum kept returning voluntarily to support the people there.

Etty Hillesum had the opportunity to go into hiding but refused. She wanted, as she said herself, to share the fate of her people. Even when friends urgently advised her to hide, she did not want to save herself at the expense of others. Hillesum was against going into hiding. This conviction earned her both admiration and criticism. Some critics accused her of making survivors who had gone into hiding feel unnecessarily guilty.

In the final months of her life, she seemed to somewhat revise her opinion. In July 1943, Hillesum lost her special status and could no longer leave the camp. Shortly afterward, her family was brought to Westerbork. Memoirs of Jewish resistance hero Ies Spetter later revealed that he and Hillesum helped smuggle children out of Westerbork Camp so they could go into hiding. Although Etty Hillesum accepted her own fate of deportation, she wanted to give the children a chance at a longer life. On September 7, 1943, her family was deported to Auschwitz and murdered. A few weeks later, on September 27, 1943, Etty Hillesum suffered the same fate and died at the age of 29.

During her time in Westerbork Camp, Etty Hillesum wrote two long letters describing the situation in the camp. These letters were clandestinely published in the fall of 1943. In a 2008 reissue, J.G. Gaarlandt called these letters "almost the literary monument to Westerbork."