But the gentle Undine would let the miserable maiden say no more. She threw her arms around Bertalda's neck, and said, 'Bertalda, dear Bertalda, you shall live with me and be my sister. You shall come with me to Ringstetten this very day.'
The maiden dried her tears and looked timidly at the knight. He also felt sorry for Bertalda, nor did it please him to think of her venturing alone into the forest. Too well he knew the terrors which might surround her there. He took her hand, as he saw her timid look, and said in a gentle voice, 'You shall live with us at Ringstetten, and I and my wife will take care of you. But lest the good old fisherman is troubled as the days pass and you do not reach the cottage, I will send to tell him that you have come with us and are safe at Castle Ringstetten.' Then, giving Bertalda his arm, he placed her in the carriage with Undine. The knight himself mounted his horse and rode along gaily by their side, and soon they left the city and all sad thoughts behind.
At length, one fair summer evening, the travellers reached Ringstetten. There was much to make the knight busy after his long absence, and thus it was that Undine and Bertalda spent many days alone together. Often they would walk in the beautiful country which lay without the castle grounds.
One day, as they wandered along the banks of the river Danube, a tall man came toward them, and would have spoken to Undine. But Undine, gentle as were her ways, had no welcome for the stranger. When she saw him, a frown crossed her sweet face and she bid him at once begone. Shaking his head the tall man yet obeyed, and walking with hasty steps toward a little wood, he soon disappeared.
'Is not the stranger he who spoke to you in the city, the Master of the fountain?' cried Bertalda fearfully. She would always be afraid of the man who had told Undine the secret of her birth.
'Fear nothing, dear Bertalda,' said Undine hastily, 'the Master of the fountain shall not do you harm. I will tell you who he is, and then you will no longer be afraid. His name is Kühleborn and he is my uncle. It was he who carried you away from your mother's arms and put me there in your place.'
Then, as Bertalda listened with wide open eyes, Undine told her of her childhood's home in the crystal palace under the blue sea, and of the free and careless life she had lived in the cottage by the lake. She told her, too, of the coming of the knight, and of their wedding-day, when she had won for herself a soul, a gift given to no Undine save through the power of love.