Stargate Atlantis Episode Guide

Season One
AIR DATE: 2004-2005     
A brand new team travels to another galaxy to find the lost city of the Ancients, a dark new enemy, and countless new worlds populated by humans.
Season Two
AIR DATE: 2005-2006     
After an attack by the Wraith and new contact with Earth, the Atlantis base faces key changes in leadership and personnel.
Season Three
AIR DATE: 2006-2007     
The team embarks on new adventures in the Pegasus Galaxy -- and encounters a sinister new foe.
Season Four
AIR DATE: 2007-2008     
The conflict with the Replicators becomes a galaxy-wide crisis -- and an alliance with an old enemy may be the only way to stop them.
The rogue Asgard ("The Lost Tribe") Season Five
AIR DATE: 2008-2009     
Old enemies are on the run, making way for powerful new groups to emerge from hiding.