the tardis materialises on board a vast and advanced alien spacecraft, observed by a hovering surveillance device which conveys the arrival of the crew to an observing being in control of the vessel. the tardis crew become separated and the fifth doctor and tegan reach the bridge where the green-skinned commander introduces himself as monarch, ruler of urbanka, and his associates and fellow urbankans are the ministers of enlightenment and persuasion. the leader is intrigued by talk of current earth civilisation and reveals their ship is bound for earth. shortly afterwards enlightenment and persuasion assume human forms, dressed in garments tegan designed to demonstrate contemporary earth fashions.