A new group of explorers travel to the distant Pegasus Galaxy, where it discovers the advanced but deserted city of Atlantis on the ocean floor. Stranded in a new galaxy, without the possiblitity of returning to Earth, the team encounters a group of nomadic humans and a deadly enemy that feeds on humans as an energy source!

The Stargate is an intergalactic gateway, developed by an ancient civilization, that links other planets from other solar systems to ours. The U.S. Air Force assembles a Stargate team headed by Colonel Jack O'Neill for interstellar peacekeeping missions.

The Stargate is an intergalactic gateway, developed by an ancient civilization, that links other planets from other solar systems to ours. The U.S. Air Force assembles a Stargate team for interstellar peace-keeping missions.

In the final season, Vala, a former Goa'uld host turned freedom figther, joins SG-1in their battle to defend the galaxy from the holy war of Ori. Meanwhile, relations between Jaffa and Earth continue to be strained.