A madman is holding Vitoria hostage, killing its citizens in brutal ways and staging the bodies. The city's only hope is a brilliant detective struggling to battle his own demons. Inspector Unai López de Ayala, known as "Kraken", is charged with investigating a series of ritualistic murders. The killings are eerily similar to ones that terrorized the citizens of Vitoria twenty years earlier. But back then, police were sure they had discovered the killer, a prestigious archaeologist who is currently in jail. Now Kraken must race to determine whether the killer had an accomplice or if the wrong man has been incarcerated for two decades. This fast-paced, unrelenting thriller weaves in and out of the mythology and legends of the Basque country as it hurtles to its shocking conclusion.