A young boy wants to write a story, just like his big sister. But there's a problem, he tells her. Though he knows his letters, he doesn't know many words. "Every story starts with a single word and every word starts with a single letter," his sister explains patiently. "Why don't you start there, with a letter?" So the boy tries. He writes a letter. An easy letter. The letter I. And from that one skinny letter, the story grows, and the little boy...