Colonel Jack O'Neill and Dr. Daniel Jackson reunite with new team members at Stargate Command to explore the galaxy and fight the evil Goa'uld.

When Earth discovers the Ancients' lost city of Atlantis, an international team of scientists and military personnel travel to the distant Pegasus Galaxy, where they find an entirely new network of Stargates -- and a deadly threat.

Fleeing an attack on a secret off-world base, a group of soldiers find themselves on board an unmanned Ancient ship on a pre-programmed course millions of years ago, traveling from one galaxy to the next.