Osiris meets with Zipacna on his ship, he tells her about a peace summit between all the system lords on a space station. The Tok'ra find out about it and go to Earth so that one member of SG-1 (Daniel) can sneak onto the station as a lotar of Yu. The Tok'ra plan to wipe out all of the System Lords all at once with a new poison invented by the Tok'ra - the poison only kills the symbiote. The Tok'ra have developed a different version of the Reol chemical. Daniel and Jacob go to Yu's home planet, Jacob zats Yu's lotar (Jarren), and Daniel takes his place. Daniel jabs Yu with his ring which contains the chemical so that Yu will believe that he is Jarren.
SG-1 and SG-17 go to Revanna with the Tok'ra. Daniel goes to the space station with Yu in his cargo ship, they come on board, and Daniel is just about to release the poison when he learns that another System Lord is coming. Jacob tells him to wait until they arrive - it's Osiris. Daniel doesn't release the poison, but it turns out that it was good that he didn't because if all of the System Lords were killed, Anubis (a very powerful System Lord) would be in power. The Tok'ra find out that a mother ship is on it's way to Revanna - they start an evacuation but the Stargate is active and the mother ship will arrive before the gate disengages. The Tok'ra base's power is cut so that the Al'kesh will have to resort to random bombardment; it is Zipacna who is leading the attack.
The tunnels are found, the Tok'ra defend the base, but they fail, Jack and Teal'c are on the surface where they see thousands of Jaffa amassing for an attack. Major Mansfield is badly injured, lt. Elliot is badly injured too, but Lantash (Martouf's symbiote that was in stasis) went inside him. Lantash is trying to heal him but he is injured very badly. They try to escape but are trapped. And Osiris confronts Daniel, having recognized him...
(To be continued)