The Longest Story in the World (short story)

Summary
A young woman, ordered on pain of death to entertain The Caliph and his court with a story, tells a tale of an old man and his adopted grand-daughter, who live in a world where fantasy is forbidden. Nevertheless, the grand-daughter tells stories of their future, claiming that the old man will invent a fabulous machine to take them away from here and travel through Time and Space, growing younger as the years pass by, fighting evil and becoming a hero.

The old man does not believe her. He fears that her tales will attract attention -- and indeed, one day he returns to his home to find the guards waiting for them. The tale ends on a cliffhanger, and will resume the next night; so long as the storyteller keeps the Caliph entertained, her life will be spared.

Characters

 * First Doctor
 * Susan Foreman
 * The Caliph

Timeline
For the First Doctor: 
 * The Longest Story in the World occurs after NA: Nightshade (flashback) ''
 * The Longest Story in the World occurs before ST: The Exiles