When Hoover went to the Bureau of Investigation (its original title; it became the F.B.I. in 1935) as its assistant director on August 22, 1921, he specifically requested Gandy return from vacation to help him in the new post. Hoover became director of the Bureau in 1924, and Gandy continued in his service. She was promoted to "office assistant" on August 23, 1937 and "executive assistant" on October 1, 1939. Though she would receive promotions in her civil service grade subsequently, she retained her title as executive assistant until her retirement on May 2, 1972, the day Hoover died. Hoover said of her: "if there is anyone in this Bureau whose services are indispensable, I consider Miss Gandy to be that person." Despite this, Curt Gentry wrote: