Born in 1882, Hélène Brion was a leading personality in the Parisian labour movement. The study of “Choses et Gens de Russie Rouge,” an unpublished manuscript testifying of her journey in Soviet Russia, of her correspondence, and of other sources, throws a new light on the militant environment of the first congresses of the international communist movement. The paper focuses on the strong experience that consisted of the daily life in Moscow and Petrograd, and on the mechanisms of conviction and disappointment in these times pioneering the reception of western travelers. The study wonders as well about a feminine and feminist commitment in the first French communism.