Season 1 Episode 02 - Children of the Gods 2

Led by Colonel Jack O'Neill, SG-1 go through the gate to the planet Chulak. General Hammond gives them a deadline - if they don't return in a certain period then a nuclear warhead will be sent through and the Gate sealed forever. They are soon taken prisoner and tossed in with other slaves, where they discover that Sha're is now Apophis' queen. Her body has been taken over by the hideous snake creatures, known as Goa'ulds, who rule the planet and collect life forms from around the galaxy to use as hosts and slaves.

Jack believes he sees the spark of freedom in Apophis' chief Jaffa, Teal'c. When Teal'c is ordered to kill all the prisoners, Jack makes a desperate appeal and Teal'c turns upon the other Jaffa. They escape in the confusion, taking Teal'c with him, and heading for the Stargate. With only minutes to spare before Hammond sends the warhead through, they get there just as Apophis is preparing to depart with his new bride and the captive Skaara. Jack manages to get to Skaara but it turns out he too is the host for a Goa'uld. Apophis and the others depart, and SG-1 manages to return to Earth with their new ally, Teal'c.