|Out of universe information|
Gairwyn is an inhabitant of the planet Cimmeria. Her people, the Cimmerians, are descendants from a Norse tribe, originally located on Earth thousands of years ago. Gairwyn and the rest of her people have worshiped the Norse god Thor for a long time. Cimmeria is being protected by their Norse gods, named the Asgard.
Almost a year later an unauthorized offworld activation of the Stargate on Earth occurred. They kept the iris closed, because there was no identification code send. They heard a soft thud against the iris. Captain Samantha Carter managed to determine that the wormhole originated from Cimmeria because of the signature from the Sagan Institute Box. They send a M.A.L.P. through the Stargate. Gairwyn appeared on the screen. She was begging for help because of the arrival of the Goa'uld Heru'ur.
SG-1 convinced Major General George S. Hammond to help the Cimmerians. After all, they were responsible for the destruction of Thor's Hammer. Gairwyn guided the team to a safe place. She later helped Carter and Dr. Daniel Jackson to find the Hall of Thor's Might. They needed to fulfill the Test of Worthiness. When they completed the challenges, the mighty Thor appeared. After learning of the destruction of Thor's Hammer, Thor takes Gairwyn aboard his ship. The Biliskner, a powerful Asgard Mothership, appeared in the sky and took the threat of the Goa'uld away. Gairwyn is sent back to the planet and told SG-1 that Thor has saved the Cimmerians from the Goa'uld. Thor has also promised her to install a new Thor's Hammer. (SG1: "Thor's Chariot")