Locate Loki

‘It is presumed that this was Loki Laufeyiarson, who has done
most evil among the Æsir.’

Then spoke Gangleri: ‘It was quite an achievement of Loki’s
when he brought it about first of all that Baldr was killed, and also
that he was not redeemed from Hel. But was he punished at all for
this?’

High said: ‘He was requited for this in such a way that he will
not soon forget it. The gods having become as angry with him as
one might expect, he ran away and hid in a certain mountain, built
a house there with four doors so that he could see out of the house
in all directions. But in the daytime he often turned himself into
the form of a salmon and hid in a place called Franangr waterfall.
Then he pondered what sort of device the Æsir would be likely to
think up to catch him in the waterfall. And as he sat in the house
he took some linen thread and tied knots in it in the way in which
ever since a net has been. A fire was burning in front of him. Then
he noticed that the Æsir were only a short distance away from
him, and Odin had seen where he was from Hlidskialf. He
immediately jumped up and out into the river throwing the net
down into the fire. And when the Æsir reached the house then the
first to enter was.the wisest of all, called Kvasir. And when he saw
in the fire the shape in the ashes where the net had burned he
realized that it must be a device to catch fish, and told the Æsir.


- Prose Edda, Gylfaginning