When Gordon first showed up at the deserted asylum he was posessed by "Simon" who's voice we hear on the end of the tape. It made him kill his wife and baby at the end of the first day. He has been living at the hospital since then. It then makes him slaughter his entire team prior this he despatches the last worker who shows up as a replacment for one of his unknowingly earlier victims, before "Simon" deserts him. Gordon realizing what he's just been made too do suffers a complete mental breakdown and is left alone in "Simon" is old room talking to his broken mobile as dusk sets outside and the recording of "Simon" states that "He" leaves in the weak and wounded.