The entire story, set in the early Sixties, is narrated as a flashback by Ralph, a retired mailman. When Stanley and Charlie, two bored postal clerks working in a large Post Office in Downtown Manhattan, united by the same passion for booze and gambling, cast their eyes on Larry, a naïve mailman, to make one of their frequent bets, they can hardly imagine that their innocent pastime would have so many devastating consequences. The bet is about the chances that Larry might or might not be lured to carry out an absurd mission concocted by the two clerks. Against all realistic expectations, it turns out that Larry, motivated by a deep love for his job and by the fact that he is led to believe that the entire country is depending on him, decides to take seriously the challenge, in spite of the enormous difficulties facing him. Throughout the book, the Author never misses an opportunity to highlight the differences between Larry and his tormentors. It soon appears that while most of the people of the Post Office drag their feet to go to work, showing very little interest in their job, Larry is always eager to grab his bag and begin his daily delivery. Given his gentle nature, everybody along his route is a friend of his, sharing with him the good and the bad moments of their life. Luckily for him, some of these friends, whose peculiar personalities are fully described in the course of the story, don’t hesitate to help him when the events originated by the bet are becoming too difficult for him to bear.
The oddest situations that evolve as result of the bet keep on surprising the Reader. As the preparations are underway, Larry’s increasing involvement in the fake mission triggers a series of events attracting the interest of more and more people, including agents of the CIA. Driven by different motivations, even foreign governments become involved in the absurd affair. Not everybody reacts in the same way. Some see an advantage in Larry’s carrying out his mission and resolve to help him. Others, instead, won’t hesitate to use all means at their disposal to stop him. With the Cold War tension at its peak, naval units of the United States and the Soviet Union come perilously close to a dangerous confrontation in their effort to monitor Larry’s moves. But the surprises for the Readers don’t end here. Amid so many unforeseen situations, the Author decides to introduce them to the fantastic world of the letters that fill the bags of the common mailmen. Only Larry seems to be aware of the fact that those written pieces of paper, sheltered by envelopes of all colors and sizes, hold an incredible secret that goes beyond any human perception. When he tries to explain this fact to his colleagues at the Post Office, he becomes the object of further derision. Ultimately, when the letters become the real protagonists of the story, the Reader will discover that Larry was right.