Season 1 Episode 10 - Thor's Hammer

While seeking allies, Teal'c suggests they travel to the planet Cimmeria - the Goa'uld have unanimously declared it off-limits as it is claimed to be the home of the legendary Norse gods. When SG-1 arrives, Teal'c is teleported away in a blaze of light - Jack leaps into the beam and is teleported away with him. They find themselves in an underground labyrinth created by the Norse gods, specifically Thor. It soon becomes clear that there is no escape - a mysterious gate bars the entrance, and while Jack can pass through it with ease, it triggers off of the Goa'uld larva in Teal'c - Teal'c can't pass through it without dying. Worse, they encounter Unas, a savage creature of the species that the Goa'uld used as their original hosts. Kept alive by his symbiote, the Unas has been trapped in the labyrinth and seeks to kill Jack and Teal'c.

As Jack and Teal'c fight for survival against their rapid-healing foe whose toughened body makes him practically immune to bullets, Daniel and Sam make the acquaintance of Kendra, a local woman who was a former Goa'uld host but escaped the labyrinth when the gate (Thor's "Hammer") killed the symbiote within her but who left her alive.

With Kendra's aid, Daniel and Sam eventually find the exit from the labyrinth. Teal's and Jack have made their way there as well but there is no escape for Teal'c. When the Unas attacks, Teal'c throws himself and his opponent into the beam - with the death of its symbiote the Unas dies and Jack pulls Teal'c out in the nick of time. Although weapons don't function within the labyrinth, Daniel uses Teal'c staff weapon to blast the Hammer apart from outside, destroying the mechanism. Kendra is leery of what the destruction of the Hammer portends, but the team departs after giving her a box they ask her to give to Thor should he ever return.