Two young noblemen, Diego de Carriazo and Tomás de Avendaño, decide to temporarily abandon their comfortable lives to experience the world firsthand. During their adventure, Tomás falls in love with Costanza, a young scullery maid of extraordinary beauty and virtue who works at an inn in Toledo. Throughout the story, deceptions, hidden identities, and moral trials intertwine until Costanza s true origins are revealed, allowing social order to be restored and true love to be fulfilled. The novel concludes by affirming that virtue and true nobility transcend birth and social standing.