Members of SG-1 become infected with an alien virus that turns them into primitive beings. Dr. Fraiser must find a cure to save the team and the alien population from whom it was contracted.

Daniel is taken captive by an alien with a hidden agenda, while SG-1 is made to believe he is dead.

The SG-1 team rescues a group of advanced humans from a planet near destruction, and must find a new home for the refugees before the Pentagon gets their hands on them.