On the newly contacted planet Pangera, SG-1 is offered a deal for a miracle medicine, and they eventually discover that the source is a captured Goa'uld Queen. Worse, the Pangerans don't have enough of the medicine, Tretonin, and what they have is only a temporary effect that requires continued dosage to sustain.
The Tok'ra agree to help but Teal'c and Jonas discover that the captured Queen is Egeria, who created the Tok'ra 2,000 years ago on Earth and is now on the verge of dying. The Tok'ra can't find a cure to the Tretonin and want Egeria released because of her founding status and to deal with their own problems with dying out.
One of the Tok'ra, Kamel, sacrifices herself to let Egeria take over her host body and let her give voice, forgive the Pangerans for their experimentation on her, and explain her own self-corrupted genetic structure is to blame for the failure of the Pangeran cure. She gives them the solution to the problem with the Pangeran medicine and the two planets part on good terms.