Marie was freed in 1941, having served as an officer in both World Wars. Refusing Vichy politics on his return to Seine-Maritime, he resigned all his elected offices, and in a letter to his constituents, explained that he could not exercise his mandate while the people could not be consulted freely. As a member of the Georges-France resistance network, he was denounced and arrested on 12 September 1943 by occupation authorities, imprisoned at Compiègne, then deported to a camp at Buchenwald on 16 December 1943, where he remained until the liberation of the camp by American troops on 11 April 1945. He had lost 30 kilograms, and had suffered a heart infection and a liver infection.