Naples, Nowadays. In a city where life unfolds amidst a ceaseless clamor of people, beeping scooters, color and beauty, there is a place where silence and history cloak the visitors transporting their souls in a 3000 year-old journey: the vast underground city, where huge spaces alternate with impenetrable, claustrophobic dark caves, galleries and alleys. Cécile Bonnet, young offspring of a family of French entrepreneurs, arrives in town for her fist big assignment: to oversee the construction of a series of mega-car parks in the tufa caverns. Helping Cécile is Yanis, her project manager/casual lover, Greta, her father's attractive assistant, and Neapolitan technical consultant Gianni. A series of unexpected events, violent deaths, involving mysterious presences brings Cécile and her team trapped forty meters below surface, with no means to communicate with the outside world. With their very life at stake they sets off on a desperate journey to find a way out of that surreal world.