Season 2 Episode 18 - Serpent's Song

Pursued by Goa'uld, Apophis, throws himself on the mercy of SG-1. Despite his past evil, SG-1 grant him sanctuary. Apophis, who shows signs of having been tortured, is slowly dying and reveals that he is being pursued by an ancient and powerful Goa'uld named Sokar, the original god of death.