After Vala Mal Doran removes the Kor mak bracelets binding Dr.Daniel Jackson and her together, they go their separate ways, only to pass out again soon after. The only chance to save them is to see the scientist examining the bracelets. However, in order to get him to help, they must run a series of ever more dangerous errands.
Lt. ColonelCameron Mitchell is ambushed and captured by a group of legendary rebel Jaffa known as the Sodan. However, because he supposedly killed one of their own before he was captured, he is challenged to Kel shak lo, a Sodan battle to the death.
A seeming glitch in a Stargate throws SG-1 off course and onto another planet. After finding a way around it, they discover a lab with a man in stasis named Khalek. They soon realize, however, that he's a genetic hybrid created by Anubis.
SG-6 returns to Earth from investigating a planet visited by a Prior, they inadvertently cause a plague that soon spreads beyond Stargate Command to the unsuspecting public. Orlin returns in the form of a child and tells the Tau'ri the truth about the Ori.
With the plague rapidly spreading to the corners of Earth, SG-1 plan on using a new disruptor device to capture a Prior on the Sodan world, the same Prior who started the plague. Gerak, leader of the Jaffa, has been turned into a Prior to give the Jaffa the chance to accept Origin.
The Galarans have the technology to implant memories into people's minds. When Lt. ColonelCameron Mitchell wakes up with the memory of murdering one of the scientists behind its development, SG-1 must help prove that it is not really his memory and that he is innocent.
SG-1 returns early from a routine mission, believing differently than Major GeneralHenry Landry key details about their mission. Then the real SG-1 returns at their correctly scheduled time. Soon, other SG-1s from alternate realities begin arriving and the real SG-1 must find a way to get them back to their own realities, but not all is as it seems when the first alternate team have plans of their own.
SG-1 goes to Camelot, after finding its address from Arthur's Mantle, in the hopes of finding a means to stop the Ori before they arrive in the Milky Way. Meanwhile, a new Supergate is discovered, where they plan to prevent the Ori from dialing in, but they are too late.