Plot

SG-1 returns early from a mission only to realize that they and Gen. Landry aren't on the same page as far as the the mission they've just completed is concerned. The confusion is quickly resolved when the "real" SG-1 returns at the correct time. Dr. Lam examines them all and concludes that they are identical and thinks they might be clones. Sam, however, thinks they may have come from a parallel universe as the result of the black hole they created when they destroyed the Ori beachhead. As more SG-1 teams arrive from other alternate universes, one of them includes Dr. Fraiser and another includes the Tok'ra Martouf. It's left to Sam and Martouf to find a way to send them all home.—garykmcd

SGC is baffled as several 'fake' SG-1 and a few other SG-teams keep arriving through the Stargate, which has to be blocked. The various Carters and Dr. Lee realize this must be the result of an a time-space singularity, presumably triggered by a black hole, causing a one-way passage between parallel universes which prove different in many details -like uniforms- and some more significant ways, like a live Dr. Janet Fraiser urgently needing help to cure a Prior plague and Carter's beloved Tok'ra, Martouf. Key proves to be the black-uniformed SG-1, whose Carter inspires a joint mission using the Prometheus, which proves an elaborate trap as they hijack it to save their own universe, resulting in a battle of matching wits.—KGF Vissers

Multiple SG-1 teams begin coming through the gate, each one from a different parallel universe. Carter teams up with Martouf (Tok'ra), who in his reality joined the SGC, and Kvasir (Asgaard) to try and figure out a way to repair the damage that was done so that more alternate SG-1 teams do not become stranded.—Kaele