Season Three
Jacob Carter comes to Earth, The Tok'Ra are unable to locate one of the System Lords, Seth or Setesh. They fear he may be hiding out on Earth. Jacob has been chosen for the mission for another reason, Selmac, his Tok'Ra symbiote is annoyed that Jacob and his son Mark haven't spoken for years.
Teal'c tells a Jaffa joke!
Teal'c: "Because the creature represents Setesh, the helms of the Setesh guard have continued to be the source of many jokes among the Jaffa."
O'Neill: "Jaffa jokes? Let's hear one of them."
Teal'c: "I shall attempt to translate one, O'Neill. A Serpent guard, a Horus guard, and a Setesh guard meet on a neutral planet. It is a tense moment. The Serpent guard's eyes glow. The Horus guard's beak glistens. The Setesh guard's nose drips."
Daniel's research suggests that Seth could still be on Earth and SG-1 travel to Seattle to investigate a cult.
They meet Jason whose son Tommy is a member of the cult.
Jack, Sam and Daniel infiltrate the cult after coming up with a plan to defeat the mind controlling Nishta gas that Seth uses on his followers.
After defeating Seth and rescuing the cult members including Tommy, Jacob and Sam go to visit Mark.