In the historic city of Vitoria, a series of ritualistic murders reawakens old fears. The crimes perfectly mimic those of a notorious serial killer who was imprisoned twenty years ago. Inspector Unai López de Ayala, a brilliant criminal profiler, is tasked with stopping the killings. He finds himself in a desperate race against time, chasing a ghost who knows the city's ancient secrets and seems to anticipate his every move. Is this a copycat, or is the real killer still at large? Unai must confront dark legends and his own past to unmask an enemy who is always two steps ahead.