S1, E4: O'Neill and the SG-1 team head through the Stargate to a planet known as P3X797 and discover a world divided between a dark and light side with a population similarly split between the Touched and the Untouched. The Untouched who live on the bright side are humans a Bronze Age people who seem almost like the Minoan civilization of Earth. The Touched who live on the dark side are heavy-browed primitives with limited skills and the brutal instincts of animals. The findings would only be of academic interest but when the SG-1 team returns all but Teal'c and Jackson begin a startling transformation: they develop the heavy brows and act with the animal brutality of the Touched. Worse so do many others at Stargate's mountain headquarters including General Hammond. As order breaks down and the project is jeopardized Jackson and Teal'c head back through the Stargate in an attempt to discover the reason for this mysterious transformation. Is this a disease that can be cured or are O'Neill the General and the others all doomed to live out the rest of their lives in the Stone Age?