The Tok'ra Martouf arrives at the SGC with troubling news: Maj. Samantha Carter's father, Jacob, and his Tok'ra symbiote, Selmak, have been captured by the evil Goa'uld system lord Sokar. Jacob/Selmak is imprisoned on a moon called Netu — which Sokar has transformed to resemble the Biblical Hell. The Tok'ra believe that Sokar plans to launch an attack against the other system lords, gaining full control for himself. Martouf will try to rescue Jacob/Selmak, but his first priority is finding out how much Selmak knows about Sokar's plan. Unfortunately, no one has ever escaped from Netu. No one except Jolinar, and she never told anyone else how she did it. SG-1 and Martouf travel to Netu on a starship. En route, Martouf uses Tok'ra technology to access any of Jolinar's memories that might still be in Carter's mind. However, what Carter recalls are painful remembrances from her own past, and dark secrets that Jolinar never wished for Martouf to know. Once they reach Netu, Teal'c stays aboard the ship while the rest of SG-1 and Martouf search for Jacob/Selmak through the underground caverns of Netu ... but the unexpected appearance of an old foe foils SG-1's plan.