Maisie could never be quite sure when she first met Hamilton, but most likely it was when she started talking to herself as a lonely seven-year-old. She didn't know his name until much later, when she was fourteen and Dr. Kane had to pay her a visit. "Let us use our horse sense," he said, and at that moment Maisie saw a great horse galloping past him and all the time looking at her, its eyes full of knowledge and its lips drawn back as if in laughter. Soon after, Maisie adopted the name Hamilton for her new and secret companion. Of course, she couldn't talk about Hamilton to anyone -- but she could write about him. And write she did, with results that would eventually broaden her horizons far beyond the confines of the small town where she had spent her lonely girlhood. Hamilton would continue to be a pillar of Maisie's life for years, as she deals with the adult problems of work, love, and marriage and builds a life for herself.

Goodbye Hamilton picks up where Hamilton leaves off. By the time Maisie reaches her early thirties, she's escaped a disastrous marriage and become a bestselling author with her very first book: all about Hamilton, the remarkable horse who exists only in her imagination but had nonetheless proved a real guide, philosopher, and friend since her childhood. Now she's about to be married again, this time to a man whose deep and abiding love for her knows no bounds. And Hamilton, in turn, marks the occasion by taking a wife himself, an elegant (and equally imaginary) mare named Begonia.

So the outlook was fair, but it seems Maisie was destined never to know happiness untouched by sorrow, and the next few years would bring their share of fresh troubles -- some a legacy from the past -- to face and fight. But Hamilton and Begonia are there to back her up, and at a time when things are looking especially black, a very real flesh and blood boy (with a surprisingly deplorable vocabulary) comes tumbling into her life, providing the greatest support and joy of all.