Isabel, the Holy Queen, is the wife of D. Dinis I, the King; and mother of Afonso IV, the Heir, both involved in a civil war that affects the country. In the midst of this disorder, Maria Afonso, the King’s youngest bastard daughter, dies in the convent of Odivelas. Disgusted with the death of his favorite, D. Dinis asks Count Lopo Aires Teles to conduct an investigation to find the culprit.