Stargate SG-1: Season 1, Episode 1

1 - 1: Children of the Gods

The System Lord Apophis launches an attack through the Stargate, tucked away by the military after the events of the movie, and the SGC program is reactivated and given a new objective - seek out and find the alien invaders and defeat them. Jack O'Neill is called out of retirement and sent to locate Daniel Jackson on Abydos.