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.