Víctor Moreno's pioneering documentary is a dizzying trip into the depths of the big city, a literally suburban world that is alien to most of us and yet right under our feet. There is a vast labyrinth of galleries, tunnels, sewers and transportation networks that have a symbiotic relationship with the city above, a functional and essential space but also symbolic: the unconscious of the city. Employing an innovative visual style and an exquisite, dialogue-free sound design, where any human beings are shadowy and indistinct, the film transforms documentary realism into an abstract sensorial journey.