S7, E14: Stargate Command gets a surprise visit from Jonas Quinn a Kelownan scientist and former SG-1 member from the planet once designated P9Y-4C3 and now dubbed Langara. But the circumstances of this reunion are not at all happy. Jonas tells SG-1 and Gen. Hammond that he and other scientists from Kelowna - one of three nations on his world - have been analyzing data left behind by Thanos the Goa'uld marauder who occupied their planet 3 000 years ago. They've discovered that the fuel-source ore Naquadria long thought to be native and unique to Langara is not a natural element. That's not earthshaking news but what follows is literally: Thanos initiated a process that synthesized Naquadria from the less powerful but more stable element Naquadah while the ore was still in the ground. This started a chain reaction that even now continues to convert the planet's Naquadah deposits into Naquadria. The conversion process now reaches so deeply into the planet that one particular immense Naquadria deposit is priming to explode with enough force to obliterate Kelowna and throw the world into nuclear winter. Maj. Carter goes to Kelowna with Jonas to help learn how the conversion process works so that they can find a way to stop it. There she meets Jonas' attractive assistant Kianna Cyr. Back at Stargate Command the three representatives of the joint ruling council of Langara arrive through the stargate: Eremal the representative from Tirania; Tarthus the representative from the Andari Federation; and former ambassador now first minister Dreylock of Kelowna. They meet with Hammond Col. O'Neill Dr. Daniel Jackson and Teal'c to discuss the partial relocation of their people to a world called Madronus which is willing to accept many thousands of refugees. Carter and Jonas return to SGC with alarming news. The original deposit of Naquadria was created by a freak explosion in the Goa'uld lab where Thanos created the first sample thousands of years ago. This explosion created the first vein which would simply have reverted back to Naquadah in another 10 000 years had the Kelownans not mined it. Unfortunately the Kelownans inadvertently accelerated and intensified the conversion process two years ago when they tested the Naquadria bomb. In essence the Kelownans are responsible for the possible destruction of their planet.