Prisoners

I Liked this episode, but I can't say I liked what happened in it. SG-1 are put into a very awkward situation when they are sentenced to life imprisonment on an inescapable planet (It has a stargate for incoming wormholes, but no DHD for dialing out). Given that the prison is used for all criminals, regardless of the severity of their crime, it's turned into a kratocracy, where those strong enough to seize power have done so. As such, the brutish Vishnoor is the boss of everybody except the mysterious Linea, to whom everybody listens.

Jack and Carter pay Linea a visit after she grants them her protection from the other prisoners, and find that she has a (natural) nuclear fusion power source, which could be used to power the gate and dial manually (like they did with lightning in The Torment of Tantalus in season 1). In return for this power, she wants them to set her free. She tells Sam about how she was convicted for her part in trying to cure a plague that ravaged her planet - letting Sam fill in the blanks. Another strange thing is when Linea cures a man's blindness, and upon seeing her face, he scampers away in fear. Despite this, SG-1 still trusts her and brings her through the gate with them, which is a very irresponsible thing to do. Perhaps it's Jack's black-ops training, to use any means necessary to escape, but Carter's happy to go along with it and neither Daniel nor Teal'c have any objections either.

In the meantime, a diplomatic relations SG-team are liaising with the authority that imprisoned SG-1, and even general Hammond makes his first trip through the gate to argue for their release, offering himself in their place (in vain).

When back on Earth, Carter shows Linea how to use the computer system to model the cold fusion reagents for them. Linea, clearly a polymath and genius, learns to control the computer system to do whatever she wants, while SG-3 bring back the cured blind man, who tells them who he saw when he regained his sight - 'the Destroyer of Worlds'. It turns out Linea didn't try to cure the plague - she started it, which explains the way she was treated in the prison. It's too late, though - as she escapes through the stargate, the SGC's self-destruct count reaches zero...
but doesn't blow up. Instead the whole computer system shuts down and restarts, showing the message that "all debts have now been repaid," leaving SG-1 with the knowledge that they let a mass-murderer loose on the galaxy once more.

It's an episode full of action and intrigue, but adds to the list of bad things SG-1 has done to the galaxy. Just because you're fighting goa'uld oppression doesn't mean you're shining stars.

The Torment of Tantalus

The first episode where we learn of the ancient alliance of four races - although the only one identified in this episode is the Asgard that we learned about in the last episode, Thor's Hammer. Ernest Littlefield, who went through the gate in early experiments in the 1940s, and who was Catherine Langford's fiancé, has been living alone on the planet Heliopolis for the past fifty years. During this time he hypothesised that the place was a meeting point for four peoples, and found a display showing 146 chemical elements (Catherine states that 111 were known to Earth scientists, but by this point Copernicum, the 112th had actually been discovered. The current periodic table shows 118 elements). Daniel realises that this was a 'universal language' used between the 'four great races'. Unfortunately they have to leave before he can study it in detail, but Capt. Carter is said to be building a computer model of it based on Dr. Littlefield's notes.

This is quite a nice episode because it brings back Catherine Langford, who first brought Daniel into the Stargate programme in the movie. And, the keen-eyed amongst you may have noticed the young Ernest Littlefield was played by Paul McGillion (Dr. Carson Beckett in Stargate Atlantis). His 'death', as she knew it (actually his disappearance through the stargate) was the reason she pushed so hard for the stargate programme to be revived. It's nice to see the two characters reunited even though we barely know either of them. As far as plot goes, though, this mostly just sets the story for future arcs and episodes.