In the 1980s, writer, poet, radio personality and football enthusiast Franck Venaille is diagnosed with Parkinson's disease. He decides to travel the length of the Scheldt river, to dip his hands in its source, and brings back the long epic poem La Descente de l'Escaut. Today, the disease has progressed, but Venaille still spends much of his time working in the study where he wrote the text. Je me suis en marche is both a road movie weaving together the poem, Venaille now and during his journey, and a documentary adaptation of the epic odyssey of a sick man retracing a river across 450 kilometres.