A troll had once taken up his abode near the village of Kund, in the high bank on which the church now stands, but when the people about there had become pious, and went constantly to church, the troll was dreadfully annoyed by their almost incessant ringing of bells in the steeple of the church. He was at last obliged, in consequence of it, to take his departure, for nothing has more contributed to the emigration of the troll-folk out of the country, than the increasing piety of the people, and their taking to bell-ringing. The troll of Kund accordingly quitted the country, and went over to Funen, where he lived for some time in peace and quiet. Now it chanced that a man who had lately settled in the town of Kund, coming to Funen on business, met this same troll on the road.
“Where do you live?” asked the troll.
Now there was nothing whatever about the troll unlike a man, so he answered him, as was the truth—
“I am from the town of Kund.”
“So?” said the troll, “I don’t know you then. And yet I think I know every man in Kund. Will you, however,” said he, “be so kind as to take a letter for me back with you to Kund?”
The man, of course, said he had no objection.
The troll put a letter into his pocket and charged him strictly not to take it out until he came to Kund church. Then he was to throw it over the churchyard wall, and the person for whom it was intended would get it.
The troll then went away in great haste, and with him the letter went entirely out of the man’s mind. But when he was come back to Zealand he sat down by the meadow where Tiis lake now is, and suddenly recollected the troll’s letter. He felt a great desire to look at it at least, so he took it out of his pocket and sat a while with it in his hands, when suddenly there began to dribble a little water out of the seal. The letter now unfolded itself and the water came out faster and faster, and it was with the utmost difficulty the poor man was able to save his life, for the malicious troll had enclosed a whole lake in the letter.
The troll, it is plain, had thought to avenge himself on Kund church by destroying it in this manner, but God ordered it so that the lake chanced to run out in the great meadow where it now stands.
Origin of Tiis Lake – Scandinavian Folktale