From Stargate Wiki
Scanning for and removing any being with a Goa'uld symbiote
- "Thor brought our people here and made this to keep us safe!"
- — Gairwyn
The device has an obelisk at the Stargate which activates when someone travels through scanning each individual, when it locates a Goa'uld or a Jaffa, the person experiences intense pain and then they are transported into the labyrinth where the only exit is to pass through the Hall of Mjolnir where the hammer is located. The device was diabled by SG-1 to free Teal'c from the labyrinth and was later destroyed by Heru'ur's forces. (SG1: "Thor's Hammer", "Thor's Chariot")