A few years later she quit her job to become a journalist at Ce Soir, a left-wing evening newspaper close to the Popular Front government.

She wrote a series of short stories under male pseudonyms (Jean Le Guern, Auxois), published on clandestine press by Les Editions de Minuit in 1943, under the title Contes d'Auxois.

She then became a pioneer of women's history in France, working mainly on feminism during the 19th century and on significant female figures such as Joan of Arc, Pauline Roland, Louise Michel and George Sand.

In 1954, Paulhan, an admirer of the Marquis de Sade, made to Desclos the remark that no woman was capable of writing an erotic novel.

After much speculation, Desclos publicly admitted that she was the author only 40 years later, and suggested that Thomas inspired her to create some characters, especially the one of Anne-Marie.