The Marine Worlds Carousel, a carousel with aquatic animals and sea carriages, is a piece among others in the heart of the project of the Machines of the Isle of Nantes that supposed to structure the urban plan of the centre of Nantes. The development of the 337 hectares brownfield area lasted over 20 years. The documentary tells the story of this phantasy world and examines how a work of art can shape a city and influence the lives of an entire community.