Stargate SG-1: Season 2, Episode 18

2 - 18: Serpent's Song

Pursued by Goa'uld, Apophis throws himself on the mercy of SG-1. Despite his past evil, SG-1 grants 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.