The films delves into the bowles of the Barcelona underground following Laura (Natalia Azahara), a young woman who has recently started to work there. They have assigned her the old and quiet Rocafort Station, but it will not take long for her to discover that this stop is home to a legend that will begin to haunt her: many people have died there in strange circumstances over the years and nobody seem interested in knowing the truth. Laura will ask for help to Román (Javier Guitérrez), a hardened ex-policeman who harbors his own demons related to Laura's case and who will try to find out what is going on. Little by little , Laura will discover that whatever happens down there, at Rocafort Station, is still happening and she doesn't want to stay there. Whatever is at that station will go after her and everyone she cares about.