Reconnaissance has discovered an alien invasion force with plans of conquest for planet Earth. Caught in a firefight, the escaping team from Stargate Command unknowingly allows a mysterious serpent-headed Goa'uld Lord access into the SGC. The invaders lay waste to the debarkation chamber, while locking a naquadah-laced bomb onto the Stargate. In the resulting attack, Colonel Jack O'Neill finds himself on a distant world, face to face with a thousand Goa'uld warriors. With the SGC under lockdown and O'Neill already a prisoner of war, the SG1 team must find a way to remove a doomsday bomb from the gate and rescue him from a Goa'uld fortress.