Can death be a form of art? Comisario Ruiz is on leave from the force. It's the festival in the capital and everybody is having fun by the Manzanares river. But the discovery of animal corpses killed by ritualistic methods is the first sign of an anomaly that will soon lead to another morbid event, the apparently ritual execution of a young art student at one of the river's weirs. And she won't be the only one. the police investigate different theories, but events begin to create a series of circumstances that will take Comisaria Ruiz to the history of Goya, weaving a frightening tangle she must resolve. Can death and art be related? Can madness become creation? With no team, no uniform and no weapon, María Ruiz must face a highly intelligent and obsessive opponent.