On the Guajira peninsula in northern Columbia the old traditions of the indigenous Wayuu still hold sway. As soon as they begin menstruating, young women have to go and spend a year in a simple hut where only a few women are allowed to visit them. Contact with men is taboo. The grandmother is chiefly responsible for preparing the girl for her role as a woman during this period of seclusion. Pili is 12 years old when, for her grandmother's sake, she decides to follow this custom. But does she really know what she is taking on? The men from her small village build the mud hut which she will not leave for the next twelve months. For the first few days she lies motionless in her hammock, only moving for ritual washing and to take special medicine. Children play and laugh in the village outside but laughter is forbidden for Pili. People come regularly to give her instruction. The twelve moons seem to be endless. Pili weaves and weaves and weaves to pass the time. When she finally emerges into the glaring light of the sun, she has visibly changed. A striking documentary about ancient customs in a modern world.