Within the ruins of the legendary city of Atlantis is buried a secret base left by the Ancients, originators of the Stargate. A new team of explorers travel to the distant galaxy where Atlantis is located, where a primitive human civilization is threatened by a sinister enemy.
The Siege (Part 3 of 3): The Atlantis team are back, facing the impending destruction of the lost city. There's no respite as the Wraith plan a fresh assault... (S2, ep 1)
A mysterious intruder has infected the Daedalus' computers with a virus that may allow it to take control of the ship. Cracking sci-fi action. (S2, ep 2)
A fierce warrior on the run could be the team's only hope in saving Ford, who's been infected by the Wraith. Top sci-fi action. (S2, ep 3)
A technical glitch during their rescue from a Wraith ship forces McKay and Cadman to co-exist inside McKay's body. (S2, ep 4)
The team visit a technologically advanced planet. And oddly, its inhabitants remain unharmed by the Wraith. Top notch sci-fi. (S2, ep 5)
McKay stumbles onto a new, potent source of energy for Atlantis based on Ancient technology. But it's yet to be perfected... (S2, ep 6)
Dr Beckett experiments with a 'retrovirus' that could turn Wraiths back into humans, but his formula causes an unexpected and dangerous reaction. Sparky sci-fi. (S2, ep 7)
Dr Beckett realises that the 'retrovirus' Ellia ingested is now in Sheppard's bloodstream... and he's mutating into the very creature that attacked him. (S2, ep 8)
The crew discovers a decrepit warship whose ancient crew are frozen in stasis pods and live in a virtual world. But it's a world infiltrated by a Wraith in disguise... (S2, ep 9)
Exploring a new planet, Sheppard and his crew find Ford living in a cave, under the influence of a powerful drug and planning revenge on the Wraith. (S2, ep 10)
The enzyme's grip on the team begins to lessen, sending them into withdrawal as they try to escape from the Wraith hive ship. (S2, ep 11)
Sheppard is pulled through a mysterious portal and trapped in a world inhabited by ancestors of the Ancients, where a violent beast is on the rampage. (S2, ep 12)
The team races against time to foil the Goa'uld's plans to destroy Atlantis. Scintillating sci-fi. (S2, ep 13)
McKay gets trapped underwater in a sinking Puddle Jumper and must rely on Samantha Carter for his survival. Will he survive? (S2, ep 14)
In a kingdom that possesses Ancient technology, Sheppard finds himself a pawn in the rivalry between heirs to the throne. (S2, ep 15)
Two pods containing the minds of alien beings take control of Weir and Sheppard's bodies. (S2, ep 16)
The Atlantis crew becomes embroiled in a Genii coup. Intergalactic action. (S2, ep 17)
A young lieutenant with amnesia makes a shocking discovery about himself. Connor Trinneer (Star Trek Enterprise) guest stars. (S2, ep 18)
McKay must save the team when they are trapped on a planet with a super volcano. (S2, ep 19)
In the season finale, the Wraith that Atlantis tried to turn human reappears, and he wants to strike a deal. But is this partnership too good to be true? (S2, ep 20)