Sac Au Do

Sac au Dos, meaning Pack on the Back, is a short story by Joris-Karl Huysmans, originally published in French in 1880. The story belongs to the early phase of Huysmans's career, before the Decadent novels and the later Catholic fiction for which he became famous, and works in the naturalistic mode that he was practicing during the years of his association with Émile Zola and the broader French naturalist literary movement.

The story draws on Huysmans's own brief experience of military service during the Franco-Prussian War of 1870-71. The narrator is mobilized with the French mobile guard during the war, experiences the chaos of French military disorganization, contracts dysentery on the march, spends extended time in various military hospitals, and eventually returns home without ever having fired a shot in combat.

The story was published in the famous Soirées de Médan collection in 1880 alongside contributions from Zola, Maupassant, and the other writers of the naturalist circle. The collection was one of the founding documents of French literary naturalism.