María Valdez, known as the Virgin of San Blas because of her charitable acts and great beauty, falls in love with David Kent, an American who is in Spain to investigate the death of his father years earlier. María and Kent set the date for a wedding, but Ricardo Ruiz, an excellent duelist and rake who desires to marry María to recoup his fortunes, informs the girl that her father was killed by Kent's father in the distant past. María then decides to avenge the family honor and immediately enters into a companionate marriage with Ricardo. Kent goes to María seeking an explanation for her sudden change of heart, and Ricardo finds them together. He challenges the American to a duel, instructing his valet to shoot Kent if he seems to be gaining the advantage. But in the course of the duel, Kent extinguishes the candles, and the valet inadvertently kills Ricardo. María and Kent are reconciled and make plans to be married.