Small Victories

"Small Victories" is the season four premiere of Stargate SG-1, and is the 67th episode overall.

Plot
Confident that the destruction of Thor's ship in the atmosphere had ended the Replicator threat to Earth, SG-1 had managed to return when SGC had put up the second Stargate. They are shocked when they hear news that a Russian Foxtrot class submarine has been hijacked by creatures with descriptions matching the Replicators. As the team prepares to move out, Thor arrives through the Stargate and enlists SG-1 to aid him. The war with the Replicators is going badly, and the robotic invaders are at the doorstep of the Asgard homeworld. As O'Neill, Jackson and Teal'c go to deal with the hijacked submarine, Major Carter goes with Thor to help find a way to stop the Replicators.

At the submarine, O'Neill, Jackson, and Teal'c decide to penetrate the submarine and try to obtain some intelligence on how to stop the Replicators before they can take control of the submarine. Unfortunately, the Replicators begin to attack, and the team is forced to fall back. Teal'c is injured and at least one member of the scout team is killed. Meanwhile, at the Asgard homeworld, Carter sees the incomplete Asgard ship, dubbed the O'Neill, designed to fight the Replicators and witnesses a short, one-sided naval battle in an attempt to stem the advance of the Replicators. Currently, five Asgard ships are in battle with three Replicator controlled ships. Unfortunately, she still cannot come up with a way to defeat them. They are then contacted that the five Asgard ships have been destroyed. The Replicators aren't attacking them because Thor's ship has less advanced technology than the ones the Replicator control.

After some study from video recordings and Replicator samples extracted from Teal'cs wound, Jackson theorizes that the Replicators are made out of the same materials as the objects they consume, and since most of the Replicators are made out of the submarine, contact with the water will cause them to rust and deteriorate and short out. Unfortunately, at least one of the Replicators is the survivor from Thor's ship, and would be made from materials resistant to seawater, so the team must go back into the submarine and ensure that the surviving Replicator is destroyed before sinking the sub. Back on the Asgard homeworld, Carter suddenly comes up with a daring plan. Because Replicators are attracted to new technology, she decides to use the O'Neill as a lure to draw the Replicators into hyperspace and destroy them by making the O'Neill self-destruct. Thor balks at the plan, but eventually relents. The Replicators take the bait and are destroyed. Thor admits that the Asgard homeworld is now safe for the time being, but adds that Replicators are never fooled the same way twice, and that they will return.

Back on Earth, O'Neill and Teal'c penetrate the submarine and find the original Replicator. They destroy the Replicator, but when they try to escape, the other Replicators block their path. At the same time, the Replicators finally manage to take full control of the submarine and attempt to steer it into the open sea. O'Neill orders the forces outside to destroy the submarine and prepares for the end, but before they are overwhelmed by Replicators, Thor beams them onto his ship, saving their lives. The Replicator threat is over for now. Thor promises that when the Asgard defeat the Replicators, he will come to assist them in their war against the Goa'uld. Jack offers for Thor to come fishing but he beams them down.

Notable Quotes
Thor: The Asgard have tried to stop them. You have demonstrated their weakness may be found from a less sophisticated approach. We are no longer capable of such thinking.

Daniel: Wait a minute, you're actually saying that you need someone dumber than you are?

O'Neill: You may have come to the right place.

Hammond: Thor, with all due respect to your situation we need SG-1 here.

Carter: I could go, sir.

O'Neill: I don't know, Carter. You may not be dumb enough.

After blowing up the O'Neill together with the Replicator ships

Carter: We did it!

Thor: It was your stupid idea, Major Carter.

On board the Asgard ship after rescuing Colonel O'Neill and Teal'c

Carter: So the bugs are all taken care of down there?

O'Neill: Pretty much, you?

Carter: We kicked their asses.

O'Neill: They had asses?