SGA Season Four Episode Guide
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EPISODE #: 401 AIR DATE: 09.28.2007
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Floating in deep space with the city's protective shield failing, the team must do all they can to keep Atlantis alive. Meanwhile, a radical injury threatens Dr. Weir's life.
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EPISODE #: 402 AIR DATE: 10.05.2007
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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.
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EPISODE #: 403 AIR DATE: 10.12.2007
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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.
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EPISODE #: 404 AIR DATE: 10.19.2007
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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.
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EPISODE #: 405 AIR DATE: 10.26.2007
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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.
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EPISODE #: 406 AIR DATE: 11.02.2007
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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.
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EPISODE #: 407 AIR DATE: 11.09.2007
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During a visit to New Athos, Teyla and Dr. Keller find themselves on the run from a primitive tribe of warriors.
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EPISODE #: 408 AIR DATE: 11.16.2007
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The team meets a man with extraordinary prophetic abilities, who gives them a dark prediction about Atlantis's future. Meanwhile, the Wraith seek a new alliance with Atlantis in their war with the Replicators.
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EPISODE #: 409 AIR DATE: 11.30.2007
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Rodney McKay goes in search of his sister on Earth after she is kidnapped by the head of a powerful corporation.
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EPISODE #: 410 AIR DATE: 12.07.2007
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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.
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EPISODE #: 411 AIR DATE: 01.04.2008
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With a plan to potentially extinguish the Replicator threat, the Atlantis team must seek an alliance with a fleet of Wraith ships.
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EPISODE #: 412 AIR DATE: 01.11.2008
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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.
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EPISODE #: 413 AIR DATE: 01.18.2008
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An automated lockdown traps Atlantis personnel in various parts of the city, each of them hoping the others will come to their rescue.
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EPISODE #: 414 AIR DATE: 01.25.2008
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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.
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EPISODE #: 415 AIR DATE: 02.01.2008
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While on personal leave on Earth, Sheppard and Ronon learn that scientists have engineered a human-form Replicator – who is now on the loose.
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EPISODE #: 416 AIR DATE: 02.08.2008
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McKay, Carter, and Keller are trapped in an underground chamber while on an off-world mission, with no apparent means of escape.
!["Midway" (SGA 417)](https://www.gateworld.net/wp-content/uploads/midway-200x120.jpg)
EPISODE #: 417 AIR DATE: 02.15.2008
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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.
![Teyla dreams of Kanaan ("The Kindred, Part 1")](https://www.gateworld.net/wp-content/uploads/the-kindred-part-1-200x120.jpg)
EPISODE #: 418 AIR DATE: 02.22.2008
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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.
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EPISODE #: 419 AIR DATE: 02.29.2008
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The team is shocked when an old friend, believed to be dead, miraculously returns to them. Teyla plans an escape from Michael's captivity.
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EPISODE #: 420 AIR DATE: 03.07.2008
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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.