One: [s1e12] The Defiant

: The episode is the first to explicitly identify the Ancients as the "Lanteans" .

: This episode is noted for Dr. McKay's growth; he chooses to join the fight alongside Sheppard rather than staying in safety. [S1E12] The Defiant One

The team finds that a single Wraith survivor has remained alive for millennia by entering hibernation and periodically feeding on the ship's cargo of hibernating humans. This "Defiant One" is significantly stronger than typical Wraith due to its desperate survival tactics and is eventually able to seize control of the team's Puddle Jumper . : The episode is the first to explicitly

: The planet features yellow, firefly-like energy beings similar to those seen in the Stargate SG-1 episode "Prodigy". [S1E12] The Defiant One

"Stargate: Atlantis" The Defiant One (TV Episode 2004) - IMDb