The book opens with a pair of reunited lovers embarking on a romantic picnic in the countryside. Their happiness is short lived, however, as Joe, the narrator of the story, becomes involved, along with others at the scene, in trying to prevent a hot air balloon breaking loose from its moorings, carrying away its child passenger.
Though the child is unharmed, the incident ends tragically and the rest of the book is concerned with the aftermath of the event and most notably with the, ultimately dangerous, obsession that one of the other rescuers develops for Joe. How Joe deals with this obsession and the effect it has on his relationship throws up many questions and dilemmas throughout the book.