The Stargate saga continues as an elite military unit races back to Earth following the mysterious disappearance of two key team members, only to find themselves in an alternate reality where the Stargate has never been invented. Somewhere in deep space, the SG-1 team is in serious trouble. Two team members have vanished without a trace, and now the SG-1 unit's only hope for survival is to get back to Earth as quickly as possible. Upon touching down the team is relieved to be home, but deeply disturbed to learn that the reality they just returned to isn't the same one they departed from. In this reality, the Stargate has never been discovered and neither the government nor the military has never even heard of the SG-1 unit. But who altered the Earth's timeline, and why? Upon discovering that a malevolent alien known as Ba'al has been meddling with the planet's timeline in an attempt to conquer Earth, the team must race against time to defeat the most powerful adversary that they have ever faced.