Three bank robbers kill a guard in a heist and flee with the loot. Looking for a place to hole up, they find an isolated hut among the Iberá wetlands, on the banks of the Paraná River. The precarious house is inhabited by an elderly trapper, hermit and eccentric. The fugitives take over the hut and decide to remain hidden there for some time. Days go by slowly. Boredom, inactivity, and lack of women make the fugitives restless and irritable. One evening, one of them, Roberto, wandering around, bumps into a beautiful girl, with blond hair and very pale skin, bathing naked in the river. When he tries to get closer and start a conversation, she turns away from him and loses herself in the bush. Is she real or was it just a mirage? Upon returning to the hut, Roberto recounts what happened to his two henchmen. The old trapper then tells them the strange, tragic story of "the Irupé flower", a legend that has been circulating in the area for some years.