One day Thor travels to Jotunheim, the land of the giants.
There he meet the giant Hymer ho challenges Thor in a fishing contest. Thor accepts the challenge but wonder what they shall use as bait. The giant answers that Thor should get that himself. Thor goes out into the giants ground to find a bull. He picks out the best of them all, Himinjod, and takes the bulls head as bait.

When they were ready to departure they took Hymer's boat and row out on the ocean.
After a wile the giant thought that they had gone far enough, but Thor kept on rowing. Now Hymer became a little worried and pointed out that they soon would approach the waters of the Midgard serpent. When Thor finally stopped and began fishing the giant got even more worried, Thor used the bull head as bait and the anchor as hook and the giant began to realize what this was all about.

Thor tossed the bait into the sea and held strictly onto the anchor-rope. After a while Thor felt that he had got something caught on the rope, he began to pull in his catching that were the Midgard serpent. Thor pulled as hard as he could, braised himself against the rail and flooring. He pulled so hard that his foot went right trough the bottom of the boat.

Finally Thor got the serpent up to the surface, he started to swing his hammer Mjölner to crush the serpents head, right between the eyes. The horrified giant then took his knife and cut the rope. The Midgard serpent sank back down to the deep and Thor became furious, he hit Hymer so hard that he fell over board. Hymer had to swim all the way back to Jotunheim, where the giants live.

Thor: The god of thunder and lightning in Nordic mythology.
The Midgard serpent: A beast of the Nordic mythology that lies in a ring around the hole world.
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The original of this story is a bit longer and today it exists in at least two versions. During the viking age it must have been a very popular story because it has been carved onto a couple of runestones. The part of the story that I have carved has not been seen on a runestone until now.