An amnesiac young Lieutenant in Atlantis suffers from disturbing nightmares that he is a Wraith, only to make a shocking discovery about himself.

Michael and his Wraith faction arrive at Atlantis to propose an alliance, hoping to use the retrovirus to transform their Wraith enemies into prey.

The team desperately attempts to stop two Wraith hive ships from reaching Earth. Sheppard must rely on an old foe to rescue McKay and Ronon.

The Atlantis team must decide the fate of a colony of Wraith they have turned into humans. Dr. Weir must defend her leadership when she is evaluated by the I.O.A.

The Atlantis team investigates the disappearance of one of their allies, only to find an old enemy engineering a race of powerful monsters.

As a mysterious new illness sweeps through the Pegasus Galaxy, Teyla is convinced by a vision that the father of her child is trying to communicate with her.

The team is shocked when an old friend, believed to be dead, miraculously returns to them. Teyla plans an escape from Michael's captivity.

Sheppard returns to Atlantis after a mission and finds the city abandoned, all systems dead -- and instead of ocean, sand dunes as far as the eye can see.

Lt. Colonel John Sheppard and his team are trapped under the rubble of Michael's facility in order to rescue Teyla Emmagan. As Colonel Samantha Carter launches a team to rescue the rescuers, little do they know that Michael Kenmore is also searching the planet for the survivors.

Michael Kenmore has infiltrated Atlantis with an army of his Hybrids, and closes off Stargate Operations and the surrounded levels to prevent anyone from taking it back. His plan; take Teyla Emmagan and her child to perfect his Hybrids, and to destroy the base when they're done. Meanwhile, Lt. Colonel John Sheppard, Dr. Rodney McKay and a team try to take back the city before Michael leaves with what he wants.