Episode 137 of "Stargate-SG1"
s07e05 Revisions

On the toxic planet P3X-289, SGC finds an electric field screening a inhabitable area and SG-1 goes to investigate. They meet a boy, Nevin, who leads them to his village where his father and the others use a mental Link to tie into a central computer. The team stays with the locals, unaware that one of the councilwomen they met has quietly left . . . and no one but they remember her. Sam notices lowering power values but the computer records don't show it and her technician friend Pallan doesn't remember it either – by her calculations the dome will fail in a short while and everyone will die. The team offers the natives the chances to leave but most are reluctant to accept – Nevin and his father Kendrick first accept their invitation but then abruptly change their mind, and are convinced removing the link causes instant death. Daniels finds papers showing over 100,000 people once lived in the dome, and the protective field is shrinking – the computer has been slowly commanding them to leave the dome and die over the years so as to conserve its diminishing energy. They convince Pallan to help them as the computer programs the other townsfolk to attack SG-1. Sam and Pallan reprogram the computer just in time and the villagers evacuate.