This documentary is an exploration that accompanies the course of the river Po from its source on the Monviso all along across the vast plain. A look onto the river and the world surrounding its banks, cadenced by the words of St. John's Gospel so as to evoke a parallelism between the waters' revitalizing force and divine grace. Documentary-maker with the ability to comprehensively observe and describe the world. Devising the ecological gimmick of a journey along the longest Italian river with an unseen perspective, Olmi seizes with deep sensitivity the relation between man, nature and the supernatural.