The aim of the film is to reproduce in images the sensations and suggestions that are perceived by listening to Skardy's song of the same name Once upon a time in Marghera: a story about a child who moved to Marghera in the 1960s from Venice, where he discovers the differences between diving into canals and jumping into ponds; water is the element that unites the two realities of the city. A Marghera made of trees, mud, and groves alongside the factories, warehouses and the first occupied social centers, contrasted with Venice in the 1980s. The film tries to restore the constant alternation between what is being told and what seems to have happened, retracing the sensations evoked by the lyrics of the song: a piece of history of the city that is both musical memory and historical memory, staging the human substrate of the city of Marghera. The evocative images are accentuated by the use of black and white.