“The Devil You Know” is episode thirteen of season three of Stargate SG-1.
In the previous episode, “Jolinar’s Memories”, SG-1 went to a prison moon belonging to the Goa’uld Sokar which had been designed to resemble Hell in order to try and rescue Sam’s father.
In the process, they discovered that Apophis was no longer dead, even if he was quite badly scarred. Apophis wants to escape from Hell and regain his former power, and more. Currently, he is subservient to Sokar, a position he does not enjoy.
The Tok’ra want to stop Sokar’s forces, which are large enough for him to eliminate many rival Goa’uld System Lords. The process will also kill everyone in SG-1. Although eliminating a lot of System Lords would be good, this would simply allow Sokar to consolidate their forces and territories into his own. That would be bad.
Nice planar explosion in this.