Thor's Hammer (S01E09)

In search of allies in their battle against the Goa'uld, Col. Jack O'Neill and the SG-1 team travel to the planet Cimmeria — home to the legendary Norse gods, the Asgard. However, Cimmeria has long ago been declared off-limits to the Goa'uld, and when the team emerges from the stargate, Teal'c who as a Jaffa carries an infant Goa'uld within him, is trapped in a mysterious beam of light. When O'Neill tries to save him, both men vanish, transported to a mysterious underground labyrinth. The labyrinth is home to Unas, a vicious creature that is the original Goa'uld host — but it is also "Thor's Hammer," which is designed to kill the Goa'uld. As O'Neill and Teal'c fight for survival, Dr. Daniel Jackson and Capt. Samantha Carter try to rescue them, aided by Kendra, a former Goa'uld host who survived her own journey through the labyrinth years earlier. (Metro-Goldwyn-Mayer (MGM))