reassigned to Russia where he oversees the transfer and development of the naqahdah generator technology. McKay is again assigned to help the SGC in "Redemption" when Anubis tries to overload the SGC's Stargate with a harmonic energy pulse. McKay later makes a sincere apology to Carter for being wrong. With the discovery of Atlantis' location in the Pegasus Galaxy, McKay is assigned to Dr. Elizabeth Weir's expedition to Atlantis, serving as chief scientific adviser. He leaves his apartment and a cat on Earth, and becomes the expedition's leading expert on the Ancients, and is assigned to an exploration team consisting of Major John Sheppard, Teyla Emmagan and Lieutenant Aiden Ford. Born without the ATA gene, McKay volunteers to be the first human subject for Dr. Beckett's gene therapy and becomes the carrier of an artificial ATA gene of his own. When the Atlantis expedition is trying to send a message to Earth, McKay records, in his message, a wish that he might get along better with his sister. McKay loses Sheppard's trust in "Trinity" after he refuses to listen to Dr. Radek Zelenka and assures both Weir and Sheppard that he can make a piece of Ancient technology ("Project Arcturus") work on an alien planet, but the device explodes and destroys 5/6ths of the surrounding star system. Sheppard tells McKay that it might take a while to earn his trust back, but that he was sure Rodney could do it if he really wanted to. In the episode "The Long Goodbye" McKay claims that he is in charge should both Weir and Sheppard be unavailable or incapacitated, but Col. Steven Caldwell takes command of Atlantis to Weir's later satisfaction. Some months after the season 2 episode "Duet" where the mind of a female soldier - Lieutenant Laura Cadman - was trapped inside McKay's body, McKay starts a relationship with Katie Brown. McKay's problems attempting to resurrect Project Arcturus cause him to seek the help of his sister, Jeannie Miller, a fellow scientist whose intelligence matches his—but who lacks the worst of his most aggravating personal qualities. Though there is obvious friction in their relationship, McKay manages to reconcile his differences with his sister. When living Ancients reclaim Atlantis and ask the expedition to leave, McKay is reassigned to Area 51. Upon learning that the Asurans have taken Atlantis, McKay joins Sheppard's and Weir's team to retake the city. During "Tao