09.13 Episode 187
Airdate: January 20, 2006

An irregular energy spike accompanies an unscheduled off-world activation, and SG-1 steps through the gate at the SGC. During their briefing, SG-1's report contains peculiar discrepancies, but before they can be explained, the gate activates again, and another SG-1 team arrives. Carter suggests that the explanation lies in the multiverse theory of quantum physics. The first team is probably a duplicate that arrived from a parallel universe when a black hole ruptured subspace and created a bridge between universes. However, as they seek a way to return the duplicate team to their own world, the gate activates again and a third SG-1 team appears.

Carter theorizes that a subspace tear has caused a ripple effect across several realities, making our universe a convergence point, and soon over a dozen SG-1 teams have arrived on the base. One team includes Dr. Fraiser and Martouf, whose bittersweet reunion with SG-1 is accompanied by a plea for help in curing the Ori plague on their world. However, Carter's proposal to seal the rupture between universes would prevent any of the teams from returning home. Nevertheless, Landry approves the mission. With the help of the Asgard Kvasir, the first two SG-1 teams depart on Prometheus to deliver a warhead into the singularity.

At their destination, the alternate SG-1 team hijacks the Prometheus and locks SG-1 in the brig. It had been their mission from the beginning to enter an alternate universe, commandeer a ship to Atlantis, and steal a ZPM with which to fight the Ori. What's more, they have a way to return home. Instead, however, SG-1 regains control of the ship and scraps the mission. Now with a means to invert the subspace rupture, the team returns to the SGC where a directed energy weapon through the gate reverses the convergence effect. As each team is sent home, Landry provides Fraiser and Martouf with the cure to the plague that will save their world.

Story by: Brad Wright and Joseph Mallozzi & Paul Mullie
Teleplay by: Joseph Mallozzi and Paul Mullie
Directed by: Peter DeLuise

Guest Starring: Teryl Rothery as Dr. Fraiser, JR Bourne as Martouf, Gary Jones as Sergeant Harriman, Bill Dow as Dr. Lee, Lexa Doig as Dr. Lam, Dan Shea as Sergeant Siler, Trevor Devall as Voice of Kvasir

Reference: Alternate Reality, Alternate Reality - Ripple Effect, Asgard, Asgard Energy Weapon, Asgard Transport Beam, BC-303, Black Hole, Samantha Carter, Entropic Cascade Failure, Janet Fraiser, Kvasir, Carolyn Lam, Bill Lee, Martouf, Multiverse Theory, Prometheus, Sergeant Siler, Stargate, Time Dilation Device