Stargate Atlantis - Season 4
1 - Adrift (2)
Air Date: September 27, 2007
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.
2 - Lifeline (3)
Air Date: October 4, 2007
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.
3 - Reunion
Air Date: October 11, 2007
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.
4 - Doppelganger
Air Date: October 18, 2007
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.
5 - Travelers
Air Date: October 25, 2007
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.
6 - Tabula Rasa
Air Date: November 1, 2007
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.
7 - Missing
Air Date: November 8, 2007
During a visit to New Athos, Teyla and Dr. Keller find themselves on the run from a primitive tribe of warriors.
8 - The Seer
Air Date: November 15, 2007
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.
9 - Miller's Crossing
Air Date: November 29, 2007
Rodney McKay goes in search of his sister on Earth after she is kidnapped by the head of a powerful corporation.
10 - This Mortal Coil (1)
Air Date: December 6, 2007
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.
11 - Be All My Sins Remember'd (2)
Air Date: January 3, 2008
With a plan to potentially extinguish the Replicator threat, the Atlantis team must seek an alliance with a fleet of Wraith ships.
12 - Spoils of War
Air Date: January 10, 2008
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.
13 - Quarantine
Air Date: January 17, 2008
An automated lockdown traps Atlantis personnel in various parts of the city, each of them hoping the others will come to their rescue.
14 - Harmony
Air Date: January 24, 2008
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.
15 - Outcast
Air Date: January 31, 2008
While on personal leave on Earth, Sheppard and Ronon learn that scientists have engineered a human-form Replicator -- who is now on the loose.
16 - Trio
Air Date: February 7, 2008
McKay, Carter, and Keller are trapped in an underground chamber while on an off-world mission, with no apparent means of escape.
17 - Midway
Air Date: February 14, 2008
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.
18 - The Kindred (1)
Air Date: February 21, 2008
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.
19 - The Kindred (2)
Air Date: February 28, 2008
The team is shocked when an old friend, believed to be dead, miraculously returns to them. Teyla plans an escape from Michael's captivity.
20 - The Last Man (1)
Air Date: March 6, 2008
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.