Astrophysicists--real ones, not just the fictional ones in this film or the current theatrical release Contact--have theorized about the existence of "wormholes" that would enable humans to travel, more or less instantaneously, to any time or destination in the universe. The original Stargate starred Kurt Russell as Air Force Capt. Jack O'Neill and James Spader as linguist Daniel Jackson. In the TV sequel, a year has passed since the discovery of the ancient Earth portal called Stargate and the first-ever expedition through it to the remote planet of Abydos led by O'Neill, stoic as ever as played by Richard Dean Anderson (MacGyver). O'Neill was ordered to permanently destroy the Stargate on Abydos upon completion of the mission, through an apocalyptic explosion that would have cost the lives of the planet's inhabitants, as well as that of Jackson, a member of the expedition team who stayed behind.

At the start of tonight's episode, the now-retired O'Neill is immediately called back into active duty after Air Force guards are attacked and a female soldier is kidnapped by aliens in snake-helmets who burst through the Stargate on a secret U.S. Air Force base. Upon seeing the carnage, O'Neill admits to Gen. Hammond (Don S. Davis), the base commander, that he had disobeyed orders to destroy the portal on Abydos. O'Neill also suspects that Jackson (played by Michael Shanks in the TV version), who cracked the Stargate code, may still be alive. Doubting that the attack originated from peaceful Abydos, O'Neill dissuades the general from sending a nuclear bomb through the Stargate until the attackers can be tracked down. The general gives O'Neill a deadline, after which the Stargate on Earth will be permanently sealed to prevent any future alien incursions. Joining O'Neill on the new mission are Capt. Samantha Carter (Amanda Tapping), a brainy astrophysicist, as well as Kawalsky (Jay Acovone) and Ferretti (Brent Stait), both soldiers from the first mission. Once back on Abydos, O'Neill is reunited with Jackson, who has taken the ravishing Sha're (Vaitiare Bandera) as his wife, as well as Skaara (Alexis Cruz), a boy O'Neill befriended and treated as a surrogate son. The team learns that Jackson has discovered a giant monument of Egyptian hieroglyphics that appears to be a map of other Stargates throughout the universe.

Also privy to the map are the snake-headed aliens who attacked Earth, and who now arrive through the Stargate on Abydos, kidnap Sha're and Skaara, and take them to Chulak, a primative planet ruled by horrific snake creatures. Called Goa'ulds, these snake creatures inhabit and enslave humaniod bodies, dipatching serpent armored guards throughout the galaxy in search of perfect host specimens, like Sha're and Skaara. Despite the predictable conclusion, Stargate SG-1, leaves many character threads dangling tantalizingly. If you aren't careful, the series could definitely hook you. One parental warning: Unlike the PG-13-rated theatrical film, the Showtime movie includes on extended scene of full frontal femal nudity, though not in a sexual context.