When Major John Sheppard's team and Dr. Elizabeth Weir came to the M5S-224 intending to dial Earth, which would endanger even greater numbers of them due to the energy required to dial another galaxy, the lifeforms took preventive action. While the intruders were made to believe that they successfully returned to Earth, their minds were actually trapped in a hallucination constructed from their memories of Earth (With the exception of Teyla Emmagan, who 'shared' Major John Sheppard's illusion as she had no memories of Earth to draw on).