This is the big Sam-Jack bonding episode. Trapped alone in freezing conditions, and with Jack gravely injured, the two get very close, and it's probably the real beginning of their series-spanning not-quite-relationship. They learn about each other - well, we learn about Jack's past anyway, in particular the time he was on a black operation in the middle East some years back - and huddle together for warmth, which gives a great opportunity for a one-liner from Jack.
Despite the team being split apart for the entire episode, it still gives Daniel and Teal'c a chance to show their devotion to their comrades, losing sleep and exhausting themselves in the search operation, bringing the team emotionally closer.
Another pretty big thing about this episode is that it introduces the Earth's second stargate, which will be used in future storylines. It's a very interesting idea, as it opens up a lot of ideas for new stories, but it's never really made clear in the episode what caused the gate to send two of the team here, or why it was suddenly available in the stargate network when it apparently wasn't for the past couple of thousand years.
Despite the small plot holes, this is a great episode for all the character dynamics. It also has Dan Shea's first appearance as master sergeant Siler. Dan's been in previous episodes but only as Richard Dean Anderson's stunt double, and behind the scenes as the stunt coordinator for the show. Siler's a great character, and it's great to see Dan Shea for more than a second at a time, or from the back only.
Only a few episodes of season 1 to go, and for the next episode - Tin Man - I have the added pleasure of a brand new fan-commentary from the guys at GateWorld.