The knight looked and saw that the whole valley was being rapidly flooded. Then, all at once, he knew that this was Kühleborn's doing.
'It is Kühleborn,' he cried aloud, 'Kühleborn the water spirit, who is doing his utmost to drown us. Do you not know a spell against his power?'
'Yea, by my troth I know a spell,' answered the wagoner, 'but ere I use it, I must tell you who I am.'
'I care not who you may be,' shouted the angry knight. 'See you not that there is no time to lose. The water is rising rapidly.'
'Nevertheless,' answered the man,' you shall hear my name, for I am Kühleborn!'
He laughed a mocking laugh, and at that moment the wagon seemed to disappear, and Bertalda and the knight were struggling in the flood. Above them rose the wagoner, who was indeed, as he had said, Kühleborn. Taller and taller he towered above them, until he seemed at last to change into a great white wave.
With horror-stricken eyes the maiden and the knight saw the wave swoop down upon the noble steed, which had been vainly struggling in the water. Then slowly once more the wave reared itself higher and higher yet above the heads of the two who watched and waited until they too should be for ever buried beneath the waters.
But ere the great white wave rolled down upon them, they were saved. Through the tumult of the waters a sweet voice floated to Bertalda and the knight. Then, as the moon broke through the clouds, they saw Undine on a hill looking down into the valley.
She rebuked the waters, she even threatened the vast wave that towered above Bertalda and the knight, until muttering gloomily it vanished from their sight.
As the waters ran more quietly through the valley, Undine flew to them swiftly as a bird and drew them up out of reach of the water. Bidding them rest a while, for they were weary, she went a little way off to fetch her white palfrey. Then, telling the knight to place Bertalda on the saddle, she led them safely back to the castle.