SG-1 makes first contact with the planet Pangar. It seems to be a peaceful world that have recently discovered ancient Goa'uld ruins. They offer Earth their greatest discovery, a drug called Tretonin, which they say keeps them entirely disease free. In return, they want the gate addresses for specific worlds, most of which turn out to be Goa'uld home worlds. An investigation further reveals that the wonder drug is based on Goa'uld symbiotes and the Pangarans reveal another secret - they have a symbiote queen, found in the ancient ruins. When a Pangaran guard is seriously injured, SG-1 asks the Tok'ra for help. They soon realize that the queen is the founder of their race.