 After three chapters, he had a vivid idea of a boy seeing a man's beheading and finding direwolves in the snow, which would eventually become the first non-prologue chapter of "A Game of Thrones".Putting "Avalon" aside, Martin finished this chapter in a few days and grew certain that it was part of a longer story.After a few more chapters, Martin perceived his new book as a fantasy story and started making maps and genealogies.