Giacomo is a 40-year-old man who works for a big company in Milan. To avoid working on weekends, he lies about having a girlfriend whose character he creates based upon a girl he sees every morning.

Discovered by accident in one of the largest zinc and silver mines in northern Mexico, the Naica cave, filled with enormous selenite gypsum crystals, contains a highly toxic atmosphere. After years of preparation, a team of speleologists, biologists, and NASA members are exploring this natural wonder.