Between Two Fires

Between Two Fires is the ninth episode of the fifth season of Stargate SG-1.

Plot
The death of the Tollan, Omoc, and the reversal of the Tollan isolationist ways sparks an investigation by SG-1 into a deeply rooted conspiracy. After years of refusing to give Earth any of their technologies, Tollana's ruling body, the Curia, offers to give Earth as many "ion cannons" as it wants. At the same time, Narim alerts SG-1 to the strange circumstances surrounding Omoc's death, suggesting that he may have been murdered.

As it turns out, Tanith, in the service of another Goa'uld, has learned to break through the Tollan defenses- Goa'uld ships now possessing shields capable of preventing even the ion cannons from working against them- and is now manipulating them with threats. Tanith has been sent to oversee a project of building powerful weapons with the Tollan's phase-shifting technology. The Goa'uld plans to use one of the devices to penetrate the iris on the Earth Stargate, but since they cannot attack without risking the wrath of the Asgard, they intend to force the Tollan to launch the weapon.

SG-1 manages to foil the plan and destroy the research facility, which results in Tanith attacking Tollana. They offer to allow Narim to return to Earth with them, but he refuses, stating that he has led his people into a battle they may be unable to win and he must stay with them. Later on, the SGC receive a garbled transmission from Narim suggesting that the Tollan have fallen.