In the huge hollow stones worshipped as gods, she saw only profanation; and, while compelled to offer sacrifice to an imaginary deity, she in her heart addressed prayers to a superior Being, that he would condescend to enlighten those who were led astray, and assist her in her secret faith.
It was at this period that her father resolved to bestow her in marriage on the son of Xerxes, King of Babylon; and as the prince was shortly expected to arrive in Saintonge, he bade her prepare to receive her intended husband.

Eustelle heard these tidings with despair, secretly resolving never to become the wife of a heathen, such as she was certain the Prince of Babylon must be: her tears and entreaties, however, had no effect on her father, who began to suspect her change of faith, and resolved to secure the alliance at once.

Preparations on a magnificent scale were being made, and in a few days the bridegroom elect was expected to arrive, when news was suddenly brought that the prince had disappeared from his father's court, and was nowhere to be found.

The father of Eustelle hastened to her chamber to prepare her for the disappointment, when, to his surprise, he found her not; and on the couch where she usually slept a golden cross was laid; but no one could give any account of her.

The country was searched in all directions in vain; and it was at length supposed that Eustelle had destroyed herself.
It was, however, far otherwise, for, in a cavern by the side of a fountain, on the spot where now stand the ruins of the Roman amphitheatre, Eustelle had concealed herself, having been guided thither by a shining light, which flitted before her to the spot, and rested at the mouth of the cavern: there she was miraculously supported, drinking only of the waters of the fountain, which not only served her for nourishment, but so increased her beauty, that she was a marvel to behold.