Otto Frank
In 1933, Gies began working for Otto Frank, a Jewish businessman who had moved with his family from Germany to the Netherlands in the hope of sparing his family from Nazi persecution. She became a close, trusted friend of the Frank family and was a great support to them during the two years they spent in hiding. Together with her colleague Bep Voskuijl, she retrieved Anne Frank's diary after the family was arrested, and kept the papers safe until Otto Frank returned from Auschwitz in June 1945 and learned of his younger daughter's death. Gies had stored Anne Frank's papers in the hopes of returning them to the girl, but gave them to Otto Frank, who compiled them into a diary first published in 1947.