 In the Atlantis Season 3 finale episode, "First Strike", Weir is left in a coma when a beam that the Expeditions's enemies, the Asurans had created targets the Control Room of Atlantis.Weir survives although she becomes part-Replicator due to the fact that the nanites that were left in her system during the Stargate Atlantis Season 3 episode, "Progeny" have been reactivated.Weir eventually sacrifices herself to give Sheppard and his team enough time to escape during the Stargate Atlantis Season 4 episode, "Lifeline" with her fate being unknown although she later returns as a Replicator in the Season 5 episode, "Ghost in the Machine".