An old man, former clown, comes back in the neighborhood where he used to lived for the funeral of his ex-wife, and finds old friends with whom he had lost contact.

In post-war France, Jan Bojarski, a young Polish refugee, became the greatest counterfeiter of all time, the "Cézanne of counterfeit money". For more than fifteen years, this man led a double life, unbeknownst to his family, making counterfeits in a garden shed that were "truer" than the bills issued by the Banque de France... All these years, this peerless counterfeiter managed to avoid being caught by the police, and became the bête noire of Commissaire Mattei in a hunt that, for these two obsessives, turned into a duel.

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.