03E04 - Legacy

SG-1 discover nine Goa'uld corpses in a sealed chamber, Teal'c identifies the crest as the nine Linvris, minor rivals of the system lords. While reading a tablet containing page one of some war plan, Daniel unknowingly gets infected by a parasite, which gives him visual and auditive delusions back on earth. An epidemic of migraine causes the general to keep all SG-teams in the base for examination. Daniel was already in a padded psych ward cell when during a visit from the colleagues he hears Ma'chello's voice say the parasite has left to enter its real target, a Goa'uld: Teal'c, for whose symbiont it is lethal. During examination of the page turner which released the designer organism, Jack, Dr. Fraiser and Sam get infected by several parasites, only Sam is found immune, even able to kill it by hosting it. The race is on to find how and hopefully use that mechanism to save the other three infected ones...