Two invisible beings enchant and upset the life of a park: Octave, -the guide of Mr. Pilou- and Annabelle. Annabelle fascinates Octave. Mr. Pilou, unaware of the existence of Octave, walks his dog every day in the park: master and dog will be involved in funny adventures. But there is also Zoé and Lino, Mme Pauline, and Caroline the girl who sings like an angel. The Muse of music is everywhere; even the dogs are enchanted by the music. A detour leads to Paris: it is in Paris that Octave remembers tango music. This music will start to unravel his story. A scherzo of the visible and the invisible: are you alive if you are invisible?