|Original air date|
|SG-1 Season 1|
Whilst exploring Cimmeria, Teal'c and Colonel Jack O'Neill are transported to a labyrinth where any Goa'uld will die if they try to escape, leaving the host free. The two nevertheless attempt to find a way out, but are found by an unwanted visitor who will stop at nothing in killing them as it attempts to escape. Meanwhile, Captain Samantha Carter and Dr. Daniel Jackson use Kendra, a former Goa'uld host, to guide them to the labyrinth.
Through examining and comparing Norse mythology to that of the Egyptians, Dr. Daniel Jackson theorizes that there may be another race of aliens who pose as gods, but are good gods, against the Goa'uld, and, thus, a potential ally. Jackson believes that Thor was an alien, and his legendary weapon Thor's Hammer was an alien device that would be an invaluable weapon against the Goa'uld. This possibility is increased when Teal'c makes mention of a world that was banned by the Goa'uld (Cimmeria), which is represented by a hammer sign. The reason why is that any Jaffa or Goa'uld who goes there is never heard from again. Before departing, Major General George S. Hammond gives SG-1 a box to show friendship to the good aliens they will encounter.
SG-1 travels to Cimmeria, and, upon arrival, they encounter a group of people who laugh at them, and then begin chanting the name "Thor" as a giant stone hammer starts to charge.
It scans each member of SG-1 with a beam of light, bypassing Daniel, Sam and Jack before it scans Teal'c with the device, causing him to scream in pain.
O'Neill and Teal'c appear inside a cave, where a recording by Thor (in the appearance of a viking) informs them that the Goa'uld in Teal'c's abdominal cavity will die when he tries to leave the cave, revealed to be a labyrinth.
Meanwhile, Jackson and Carter, with help from Gairwyn, who came to see who had come through the Stargate, find a person who had once been in the labyrinth herself. The person, Kendra, was once a Goa'uld host, and so when her Goa'uld had visited the world before, she taunted the symbiote that Cimmeria was full of riches, she was taken to a cave, and, upon leaving, her controller was killed and she was freed.
Inside the Labyrinth, O'Neill and Teal'c realize that they are not alone in the cave. They discover that an Unas, the first host race used by the Goa'uld, is alive in the cave, and he is a dangerous foe. Since Teal'c's staff weapon does not work inside the cave, he and O'Neill rely on bullets to try to kill the alien. Though this appears to kill the creature at first, it is unsuccessful.
As Teal'c and O'Neill reach the exit of the cave, they discover that they were followed by the Unas, and, in order to kill it, Teal'c is forced to push the creature into the door of the cave, killing its symbiote (and nearly killing Teal'c's, too). Carter, Jackson and Kendra arrive soon afterwards, and in order for Teal'c to leave the cave, his staff weapon is taken outside the cave, then used to destroy the Thor's Hammer.
However, this also destroys Cimmeria's only defense against the Goa'uld with Daniel reluctantly firing a shot from Teal'c's staff weapon to destroy the defense, enabling Teal'c who had been trapped to leave the Hall at last.
Before SG-1 leaves the planet, they leave the Sagan Institute Box made of a special alloy for Kendra to give to Thor if he ever returns to the planet, in hopes that they will be able to make contact with him at some point in the future.
Apophis; Asgard; Asgard High Council; Asgard Obelisk Transporter; Cimmeria; Entry mark; Etin; Gairwyn's husband; Goa'uld; Goa'uld healing device; Hall of Mjolnir; Hologram; Horse; Immune system; Jebanna; Junior; Lightning; Marduk; Ramir; Ruax's Unas Host; Carl Sagan; Sagan Institute Box; Sha're; Skaara; Skirmish on Cimmeria; Staff weapon; Thor; Thor's Hammer; Unas; Vampire
Gairwyn: (to Carter and Jackson) You're a little short for gods.
O'Neill: Is Junior okay?
Teal'c: Yes, but the beam caused the Goa'uld I carry great pain.
O'Neill: Uh, I'm sorry to hear that.
Thor: This is your prison. Your technology will not function here. There are no luxuries, no worshipers, no slaves to do your bidding.
O'Neill: Teal'c, I think we just got the answering machine.
Thor: Only basic sustenance, and time.
O'Neill: Yeah, well, great. Thanks - thanks for the chat.
O'Neill: Water. Give it enough time and it'll bring down walls, even walls just like them. So in a couple of hundred years, we'll be free.
Ruax: Jaffa. I am Unas. The First One.
Teal'c: You do not exist.
Ruax: Kill the human.
O'Neill: Excuse me?
Ruax: And we will feast together.
Teal'c: I no longer serve the Goa'uld.
Ruax: We shall see.
Teal'c: The old stories say Unas had great regenerative powers. But those are tales told to frighten children. It is a myth, much like your vampir.
Teal'c: It is dead.
O'Neill: That's good.
Teal'c: I believe.
O'Neill: You believe?
Teal'c: I am certain.
Teal'c: I am.
O'Neill: Just a myth.
Teal'c: A myth.
Ruax: Your weapons cannot kill me! I know the secrets of the labyrinth. I could help you escape.
O'Neill: A map would be nice...
Teal'c: Are you considering the same tactic as I?
O'Neill: Teal'c, the cliché is, "are you thinking what I'm thinking?". And the answer is yes.
Jackson: Do you know what this means?
O'Neill: It's the only way out of here, Daniel.
Jackson: But what this thing can do for Sha're and Skaara...
O'Neill: Teal'c's here now.
Teal'c: And here I will remain. I was with those who took the ones you love.
O'Neill: No. You're part of this family now. We're not leaving you behind.
- The title refers to the device discovered in this episode, Thor's Hammer, but also to the superior might of the Asgard over the Goa'uld.
- Although this episode contains the first mention of the Asgard, they would not be seen in their true form until the second season episode "Thor's Chariot".
- This episode marks the first mention and appearance of the Unas, which reappear in later seasons as a civilization independent of the Goa'uld.
- This episode marks the first time Teal'c's symbiote is referred to as "Junior".
- The Sagan Institute Box is an homage to Carl Sagan, the famous American astronomer, astrobiologist, and highly successful science popularizer.
- Marduk is first mentioned by Kendra and would later appear in Season 5's "The Tomb".
- There is a moment of irony near the beginning of the episode when Gairwyn tells SG-1 that they are "a little short for gods," when in fact Thor himself is a member of the Asgard species who were very much shorter than SG-1. It may also be a reference to Star Wars: A New Hope in which Princess Leia said to Luke Skywalker, "Aren't you a little short for a storm trooper?"
- This is the first of fourteen episodes of Stargate SG-1 and Stargate: Atlantis directed by Brad Turner.
- James Earl Jones, who is the voice of the Unas Ruax in this episode, is better known as the voice of Darth Vader in the original Star Wars trilogy. As in Star Wars, Jones provides the voice while a heftier actor provides the body (here, Vincent Hammond).
- Dr. Daniel Jackson and the FRED are on the ramp to the Stargate as "chevron two encoded" comes over the speaker. Jackson may make it off the ramp before the last chevron is encoded, but the FRED has no chance of making it off the ramp before the outgoing wormhole would engage and destroy it, and yet it didn't.
- French: Le Marteau de Thor (Thor's Hammer)
- German: Im Reich des Donnergottes (In the Realm of the Thunder God)
- Italian: Il Pianeta dei Vichinghi (The Vikings' Planet)
- Spanish: El Martillo de Thor (Thor's Hammer)
- Czech: Thorovo Kladivo (Thor's Hammer)
- Hungarian: Thor pörölye (Thor's Hammer)
- Polish: Młot Thora (Thor's Hammer)