Nine years in the future, the Goa'uld have been defeated thanks to an alliance with an advanced alien race. Transportation technology and off-world Stargate travel is now commonplace. However, Carter finds out that most of the human race has secretly been rendered sterile by Earth's new allies. She and the other SG-1 team members must rig the Stargate for time travel (first done in the episode "1969") and send a message back to their counterparts in 2001 to prevent contact with the alien race.