Synopsis by Hal Erickson
The SG-1 team lands on the planet P3X797, a world evenly divided into a "dark" and "light" side. On the "light" reside the Untouched, an advanced civilization not unlike the Earth's ancient Minoans. On the "dark" live the Touched, a primitive, warlike tribe. An alien virus infects all the team members except Jackson (Michael Shanks) and Teal'c (Christopher Judge), transforming them into the brutal Touched. Jackson races against time to find both cause and the cure for this disturbing metamorphosis.