The Fourth Doctor and Sarah Jane Smith are travelling to Geshtinanna, a world of historical importance; however, Sarah is astonished to learn that their journey will take nine weeks. At first she and the Doctor amuse themselves exploring the limitless confines of the TARDIS, looking through its countless rooms and contents. But after forty-three days of travelling the ship's corridors, planning her science-fiction book and listening to the Doctor's stories, Sarah becomes bored to the point of tears, and even the Doctor has grown tired and listless.