Two cops lost in the deep south of Spain. One serial killer to catch. A lot of secrets and lies to disclose.

The story revolves around a Basque Roman Catholic priest dedicated to committing as many sins as possible, a death metal salesman from Carabanchel, and the Italian host of a TV show on the occult. These go on a literal "trip" through Christmas-time Madrid to hunt for and prevent the reincarnation of the Antichrist.

Raimunda lives and works in Madrid with her husband Paco and their daughter Paula. Raimunda's sister Sole lives nearby. The two sisters miss their mother Irene who died several years ago in a house fire along with their father. When a former neighbor from their hometown reports that she has seen the ghost of Irene, the daughters do not believe her. After a murder and a family tragedy, however, Irene's spirit materializes around her daughters to comfort them.