Set in the mid-seventeenth century, it portrays a romance between Queen Christina of Sweden and an Italian during her stay in Rome.

One evening, after a tiring hunting party, Cristina, with her entourage, asks for hospitality from the Duke of Ceri, who has recently arrived in his castle with his young wife Annamaria.

Santinelli, captain of the queen's guard and her favourite, falls in love with the young duchess.

The duchess's sister-in-law takes advantage of her situation, anxious to get rid of Annamaria, whose marriage to her duke has robbed her son of any hope of an inheritance.

Arrested and fallen into the hands of the Baron of Aversa, the young widow is taken to the Ceri castle, where she is exposed to the deadly hatred of her sister-in-law.