The Elder Scrolls: Arena

The game's setting begins in Tamriel on the 389th year of the Third Era, when Emperor Uriel Septim VII summons his advisor and Imperial Battlemage Jagar Tharn over concerns of betrayal from within the court. It transpires that his concerns were justified when Tharn is revealed to be the traitor, magically trapping the Emperor and his general, Talin Warhaft, in another dimension.