Grettir went up to the Arnarvatn Heath and built himself a hut there of which the remains are still to be seen. He went there because he wanted to do anything rather than rob, so he got himself a net and a boat and went out fishing to support himself.

It was a weary time for him in the mountains because of his fear of the dark. Other outlaws heard of his having come there and wanted to go and see him, thinking that he would be a great protection to them.

There was an outlaw from the North named Grim. This man was bribed by those of Hrutafjord to kill Grettir. They promised him pardon and money if he succeeded. He went to visit Grettir and asked for his hospitality.

Grettir said: "I do not see how you will be holpen by coming to me, and you men of the forest are untrustworthy. But it is ill to live alone; I have no choice. Only he shall be with me who is willing to work at whatever comes to hand."

Grim said that was just what he wished and pressed Grettir much, until Grettir let himself be persuaded and took him in. He stayed there right into the winter, and watched Grettir closely, but it seemed no easy matter to attack him, for Grettir was suspicious and kept his weapons at hand night and day; when he was awake the man would not venture to approach him.

One morning Grim came home from fishing and went into the hut stamping with his feet and wanting to know whether Grettir was asleep. Grettir lay still and did not move. There was a short sword hanging above his head. Grim thought he would never have a better opportunity. He made a loud noise to see whether Grettir took any notice, but he did not, so Grim felt sure that he was asleep. He crept stealthily to the bed, reached up to the sword, took it down and raised it to strike. Just at the moment when he raised it Grettir sprang up on to the floor, and, seizing the sword with one hand, Grim with the other, hurled him over so that he fell nearly senseless. "This is how you have proved yourself with all your friendly seeming," he said. Then he got the whole truth out of him and killed him. He learned from this what it was to take in a forest-man. So the winter passed. The hardest thing of all to bear was his fear of the dark.