– To save his own life, Mateo agrees to track a serial killer whose victims are found with mysterious markings.
– Mateo returns to Seville to find the illegitimate son of a late friend but is captured by the Inquisition.
– A murdered woman is found in the harbor as the plague begins to spread through the slums.
– As the city is devastated by disease, Mateo discovers a secret Protestant leader who may be behind the killings.
– Evidence grows that high-ranking officials are involved in the conspiracy.