After a horrifying PredAlien crash-lands near a small Colorado town, killing everyone it encounters and producing countless Alien offspring, a lone Predator arrives to "clean up" the infestation.

With the Ancients' city of Atlantis discovered in the Pegasus Galaxy by Stargate Command, Dr. Elizabeth Weir and Major Sheppard lead a scientific expedition to the ancient abandoned city. Once there, the team not only find themselves unable to contact Earth, but their explorations unexpectedly reawaken the Ancients' deadly enemies, The Wraith, who hunger for this new prey. Now with the help of newfound local allies like Teyla Emmagan, the Atlantis Team sets about to uncover their new home's secrets even as their war of survival against the Wraith begins.

With the Ancients' city of Atlantis discovered in the Pegasus Galaxy by Stargate Command, Dr. Elizabeth Weir and Major Sheppard lead a scientific expedition to the ancient abandoned city. Once there, the team not only find themselves unable to contact Earth, but their explorations unexpectedly reawaken the Ancients' deadly enemies, The Wraith, who hunger for this new prey. Now with the help of newfound local allies like Teyla Emmagan, the Atlantis Team sets about to uncover their new home's secrets even as their war of survival against the Wraith begins.

The story of Stargate SG-1 begins about a year after the events of the feature film, when the United States government learns that an ancient alien device called the Stargate can access a network of such devices on a multitude of planets. SG-1 is an elite Air Force special operations team, one of more than two dozen teams from Earth who explore the galaxy and defend against alien threats such as the Goa'uld, Replicators, and the Ori.