Toledo, 13th century. Francisca, an orphan girl of 15, thanks to her gift for drawing is given the privilege of being an apprentice at Alfonso X the Wise's royal scriptorium. Before her lies the shadow of of a convent she doesn't want to enter, even if that means giving up her training. However, in a city full of courtly intrigue and inhabited by people belonging to three religions, shadows darker than that one easily appear. Francisca is about to enter a plot full of darkness, spells, mysteries and betrayal, from which she will only be able to emerge using her ingenuity, forgetting her prejudices and with the help of old and new friends.