In the harsh winter of 1620 an horrific crime propagates panic through all corners of Madrid: a young woman has been raped and buried together with a heart-extirped baby.
No one doubts it has been a ritual crime, and soon appears a “libel of blood” against the scribe Sebastián Castro and his wife Margarita, a false accusation that blames Jews for sacrificing Christian kids in the elaboration of black magic rituals.
Luckily Alonso, their oldest son, has been able to escape the jaws of the Inquisition, in charge of the murders’ investigation, but now has to face other terrible dangers: the cold, the hunger and the wretched of the streets.
Hopeless, and with no other help than two beggars, Alonso will try to make true his only objective: save his fathers.