The Stargate is ancient. When a valid sequence of glyphs is tapped
in, it opens a wormhole to another planet. Many of these planets
are populated by descendants of humans. Some are enslaved by the
System Lords, the Goa'ulds - a little nasty snake creature that
takes human hosts (like an ST Trill symbiont, but bad). The System
Lords once dwelt on Earth and left behind a (mostly) Egyptian mythology.
They like to be treated as Gods. They are not.
The film Stargate starred Kurt Russell and James Spader. The TV
series picks up a year after the events in the movie. Now with Richard
Dean Anderson as Colonel Jack O'Neill - called back from retirement.
Michael Shanks as Doctor Daniel Jackson who was left by choice to
live on Abydos. Amanda Tapping as Captain Samantha Carter - military,
but also scientific genius who has worked on figuring out the stargate.
(And later promoted to Major). Joined after an adventure by Teal'c
(Christopher Judge) - a reformed high level Goa'uld who has realised
the System Lords are not in fact Gods. Overseeing Stargate Command
is General Hammond (Don S. Davis). And late addition to the team,
from another planet, is Jonas Quinn (Corin Nemec). (Though note
that in the next series, the departed Daniel Jackson is returning
and Jonas will become a regular guest, just like Dr. Fraiser (Teryl
Rothery).
This series is deservedly popular and rightly so, (even though
other series have had to make way for it). Sometimes inventive,
sometimes amusing and even self-mocking, and with long term appeal,
Stargate SG-1 continues to keep high audience ratings.