An archaeological team makes an amazing discovery - a planet holding primordial Goa'uld symbiotes. But the planet also is home to the Unas, the first race that acted as a host to the symbiote, and the team and SG-1 are soon in danger from the symbiotes.

SG-1 are brainwashed and given memories of new lives and put to work as mining slaves on an alien world. While Hammond tries to find out if they're still alive, the SG-1 must struggle with their returning memories and plot their escape.