In order to learn how to achieve Ascension, the remnants of Niam's faction decided to study Lt. Colonel John Sheppard's team and Doctor Elizabeth Weir in hopes of learning how to gain a "soul". To this end, they created Organic Asuran copies of Sheppard's team and built an exact copy of Atlantis on a planet where clouds would keep the team from being able to see that it was the wrong planet. Within the copy, they were also able to replicate all of the Atlantis expedition's equipment and took on the form of expedition members. To keep the team from learning the truth, the Replicators set the sensors on a loop so they wouldn't detect that the only life-signs were the duplicate team's and made it so that an apparent malfunction caused by McKay's work on increasing the efficiency of the Stargate caused the city's fake Stargate to go down.
After about a week of the experiment, the city was discovered by a Asuran probe sent by Oberoth. Though the Replicators managed to keep the city's sensors from detecting it, they were only able to shoot it down and not destroy it, causing the probe to crash into the Reading Room. The crash of the probe and the subsequent behavior of the Replicators drew the suspicions of the duplicate team who were able to find the room where the duplicate of Weir had just been created and use the infirmary's medical scanner to discover the presence of nanites in the duplicate Sheppard's body. Following this discovery, the Replicators told the duplicate team the truth and planned to wipe their memories and move the city to a new planet as its position had been compromised by the arrival of the probe.
Before the city could be moved, an Aurora-class battleship sent by Oberoth attacked, intending to destroy the Replicators within the city as they would not rejoin the collective. Having only been able to steal one ZPM to power the city, the Replicators were unable to raise the shield as creating the duplicate team drained too much power. The team was able to persuade Replicator Keller to let them go and she gave the team the core drive of a ship's tracking system so that the real Atlantis could track all of Oberoth's Aurora-class battleships and stop him. Shortly after the duplicate team escapes in a cloaked Puddle Jumper, the city is destroyed by the Replicator ship. (SGA: "This Mortal Coil")
Several weeks before the city's destruction, Davos showed a vision of its destruction to Colonel Samantha Carter. Due to the city being an exact copy of Atlantis, the Atlantis expedition believed that this was a vision of the destruction of Atlantis itself. (SGA: "The Seer")
|Asuran city-ship(s) · Atlantis · Atlantis' copy · The Tower · Discenna · Admah|