Jim Crace, the last English writer to make it onto the 50,000-pound ($79,700) prize's 2013 shortlist before American writers are allowed to compete for the Booker, said "Harvest" dropped into his head during an anxious 24 hours after his agent told him the novel he had been writing was never going to work.
"I owed money, so out of nowhere I had to find a new book," the 67-year-old Crace told Reuters.
On a train down to a London art exhibit from his home in the English midlands, Crace was moved by the ancient plough lines etched into the passing fields, which form the backbone of his tale about an unforeseen change which threatens a way of life.
"I walked into the first gallery and I turned right and ... I promise you I'm not making it up, the very first picture I saw was a watercolour of a Tudor enclosure," he said.
On the train home he read a newspaper article about how soya barons were seizing land in South America. Suddenly, he had the setting, an artist character and the subject matter: how forced land enclosure affected peasants in Tudor England.
"Normally I expect to struggle with a book ... but on this occasion I didn't struggle at all," Crace said. "I finished that book on the day I was due to deliver the book that had failed."
Narrative character Walter Thirsk chronicles a medieval estate whose peasants have ploughed the same fields for generations. Then strangers arrive, including an artist to sketch the land, sowing the seeds of foreboding.
Some say the plot could be a metaphor for changes announced by the Man Booker's organisers last month.
From 2014, authors from any country can compete for the award, forever skewing the landscape of a prize that was previously only open to citizens of the United Kingdom, the Commonwealth or Ireland since its launch in 1969.
Like the characters in Crace's novel, authors across the Commonwealth family who have been complacently ploughing the Booker furrow for generations have since banded together, fallen out, expressed outrage and impotence at the inevitable changes.
Crace believes the decision to allow U.S. novelists to be entered for the Booker will make it harder for writers across the Commonwealth to get recognition and damage the prize.
Booker organisers have likened the current rules to holding the Olympics without inviting China and said winners from 2014 wil be able to claim they are the world's best English-language fiction writers.
"Let's hope that happens," Crace said.
But he suspects the changes will weaken the Booker's role in the Commonwealth and it will struggle to compete for prestige against the U.S. Pulitzer and National Book Awards.
"My guess is it will be a self-inflicted wound," he said.
The former Sunday Times journalist rowed back on widely-reported comments that "Harvest" was his last novel and said he was working on a play.
Crace, a Shakespeare fan, lover of the natural world and keen country walker, said the play would be a contemporary re-telling of the Minotaur legend.
The winner of two Whitbreads, a U.S. National Book Critics' Circle award and a string of other literary prizes will find out on Oct. 15 whether he can cap his career with a Man Booker.
But in the meantime he has finally reached a point where he can step off the publishing "hamster wheel", walk the fields which inspired his "last" novel and choose whether to write any of the stories that spring to life there.
"I'm not a new agey person, but narrative is ancient and wise and generous," he said. "It's been around for so long and if you open yourself up to storytelling then very often you can end up with something just happening very, very easily."