O' Neill stays behind on a planet with Lt. Tyler, a new addition to the team, as the others escape back to Earth. They ask to immediately return to the planet with, reinforcements to rescue O'Neill and Tyler, when Gen. Hammond informs them that there has never been a Lt. Tyler on their team, and that in fact, he does not even know a Lt. Tyler. Gen. Hammond denies the return, and forces SG-1 to be looked over in the infirmary. Col. Frank Simmons appears and begins his own investigation; only his motives appear to be more sinister. So, just who is it that O' Neill is helping, and can SG-1 on Earth convince the SGC to save O'Neill and the other entity before the Goa'uld capture or kill them?