Stargate SG-1/Recap/S2/E03 Prisoners
SG-1 rescue a fleeing man, which is apparently the wrong thing to do as he was a fugitive, and due to differences in the legal system of Hadante and Earth, they end up imprisoned somewhere with a Stargate but no power or DHD. Cue prison episode.
SG-1 makes friends with Linea, who all the others are afraid of. With good reason, it turns out, since her nickname turns out to be "Destroyer of Worlds". She shows them native plants that somehow generate cold fusion power, which SG-1 plan on using to dial out. Daniel has his reservations since she apparently convinces the other prisoners to occasionally commit suicide via kawoosh, but the rest of the team just want out. At the end of the episode she vanishes for several seasons before reappearing as a one-shot character.