JK Rowling was not joking when she said her next book would be "very different" to the magical world of Harry Potter.
Last week, it emerged her first work for an adult audience would follow parish-council elections in an English market town.
The celebrated British author's first novel in five years will be called The Casual Vacancy, and will be a "blackly comic" tale of an idyllic English town at war with itself, the publishers revealed last week.
Details of Rowling's first book since the Harry Potter series had been closely guarded by her new publishers after initial news of the project was released in February.
Bookshops were last week already preparing for what one said would "obviously be a major best-seller" after Little, Brown Book Group - a subsidiary of publishing giant Hachette - said the book would be published on 27 September.
The novel is expected to run to close to 500 pages, and will appear in hardback as well as in ebook format and audiobook.
The Casual Vacancy focuses on the little town of Pagford, with its cobbled square and ancient abbey, which is left in shock when parish councillor Barry Fairweather dies unexpectedly in his early forties.
The publishers said: "What lies behind the pretty facade is a town at war.
"Rich at war with poor, teenagers at war with their parents, wives at war with their husbands, teachers at war with their pupils.
"The story follows the battle for the empty seat on the parish council "in an election fraught with passion, duplicity and unexpected revelations."
In February, Rowling said: "Although I've enjoyed writing it every bit as much, my next book will be very different to the Harry Potter series."
A spokesman for Waterstones said it was "wonderful to finally know the title and release date" of the book.
The first Harry Potter book was released in 1997, with the seventh and last published a decade later.
It became the best-selling book series in history, shifting more than 450 million copies around the world, and turned into eight blockbuster films which brought in billions of dollars at the box office.
Last month, Pottermore, the digital venture that publishes the Potter ebooks, went live and sold more than (pounds sterling)1m-worth of electronic books about the teenage wizard in just three days, smashing expectations.
The operation's director, Charlie Redmayne, said: "Everything that Harry Potter does surpasses expectations.
"She turned her back on Potter publisher Bloomsbury, saying that with the new direction of her work.
"It seemed a logical progression to have a new publisher."
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