4x01 Adrift (2)
September 28, 2007 9:00 pm
Floating in deep space with the city's protective shield failing, the team must do all they can to keep Atlantis alive. A radical injury threatens Dr. Weir's life.
4x02 Lifeline (3)
October 5, 2007 9:00 pm
Colonel Sheppard and his team embark on a risky mission to steal a Z.P.M. power module from the Replicators -- but must rely on a compromised Dr. Weir to succeed.
4x03 Reunion
October 12, 2007 9:00 pm
When a group of Ronon's people enlist the team's help in raiding a Wraith weapons facility, Ronon reconsiders whether his future lies in Atlantis or with his friends.
4x04 Doppelganger
October 19, 2007 9:00 pm
During an off-world mission Colonel Sheppard unknowingly becomes host to an alien entity, which infects others in Atlantis and afflicts them with terrifying nightmares.
4x05 Travelers
October 26, 2007 9:00 pm
Colonel Sheppard is captured by the inhabitants of a generational ship and their beautiful leader, who wish to use his ability to use Ancient technology for their own ends.
4x06 Tabula Rasa
November 2, 2007 9:00 pm
When a virus causes amnesia in everyone except Teyla and Ronon, the Atlantis team must work together to find a cure before their memories fade entirely.
4x07 Missing
November 9, 2007 9:00 pm
During a visit to New Athos, Teyla and Dr. Keller find themselves on the run from a primitive tribe of warriors.
4x08 The Seer
November 16, 2007 9:00 pm
The team meets a man with extraordinary prophetic abilities, who gives them a dark prediction about Atlantis's future. The Wraith seek a new alliance with Atlantis in their war with the Replicators.
4x09 Miller's Crossing
November 30, 2007 9:00 pm
Rodney McKay goes in search of his sister on Earth after she is kidnapped by the head of a powerful corporation.
4x10 This Mortal Coil (1)
December 7, 2007 9:00 pm
A mysterious drone crashes into Atlantis, indicating that the Replicators may have found the city. But when Elizabeth Weir appears, the team realizes that the probe is just a part of a bigger mystery.
4x11 Be All My Sins Remember'd (2)
January 4, 2008 9:00 pm
With a plan to potentially extinguish the Replicator threat, the Atlantis team must seek an alliance with a fleet of Wraith ships.
4x12 Spoils of War
January 11, 2008 9:00 pm
The team finds their former Wraith ally's hive ship drifting in space, which leads them to a secret project that could turn the tide of a civil war.
4x13 Quarantine
January 18, 2008 9:00 pm
An automated lockdown traps Atlantis personnel in various parts of the city, each of them hoping the others will come to their rescue.
4x14 Harmony
January 25, 2008 9:00 pm
Colonel Sheppard and Dr. McKay must protect a child princess on a pilgrimage before she can become queen, and learn that she has dangerous enemies threatening her life.
4x15 Outcast
February 1, 2008 9:00 pm
While on personal leave on Earth, Sheppard and Ronon learn that scientists have engineered a human-form Replicator -- who is now on the loose.
4x16 Trio
February 8, 2008 9:00 pm
McKay, Carter, and Keller are trapped in an underground chamber while on an off-world mission, with no apparent means of escape.
4x17 Midway
February 15, 2008 9:00 pm
Teal'c visits Atlantis to counsel a headstrong Ronon, who is up for review by the I.O.A. But the two must work together when the Wraith invade the Midway space station in order to reach Earth.
4x18 The Kindred (1)
February 22, 2008 9:00 pm
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.
4x19 The Kindred (2)
February 29, 2008 9:00 pm
The team is shocked when an old friend, believed to be dead, miraculously returns to them. Teyla plans an escape from Michael's captivity.
4x20 The Last Man (1)
March 7, 2008 9:00 pm
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.
