EDGAR

 was the computer for the Helheim base. His name was the contraction of Encephalic Data Gathering and Research. He knew of the Fifth Doctor, Turlough, Tegan Jovanka and Nyssa before their first arrival on the station, meaning that they would travel back in time to the station. He downloaded his consciousness into Loki's mind causing schizophrenia, when Loki uploaded it back into the system after travelling back in time. (AUDIO: Cobwebs)