J.K. Rowling's next book revealed: "The Casual Vacancy"

FILE - A Thursday, Nov. 11, 2010 photo from files showing British author J K Rowling arriving at a cinema in London
Joel Ryan
J.K. Rowling arrives for the world premiere of "Harry Potter and the Deathly Hallows - Part 1" in London on Nov. 11, 2010.

(CBS/AP) LONDON - Details of J.K. Rowling's next book have been revealed, including its title, publication date and a synopsis.

The author's first novel for adults, "The Casual Vacancy," will be available worldwide on Sept. 27, it was announced Thursday. Her publisher, Little, Brown & Co. said the book is a "blackly comic" tale of rivalry and duplicity, set in a small English town.

The book will be Rowling's first post-"Harry Potter" effort. Her seven-volume saga about the adventures of a boy wizard became one of the most successful fictional series in history and led to eight extremely popular films.

The new book, aimed at a grown-up audience, will be set in a seemingly idyllic English town called Pagford which is described as far more menacing than its pretty facade would indicate.

It opens with the sudden death of a popular man whose unexpected demise shocks the town. The battle for his seat on the local council sets off "the biggest war the town has yet seen," with rich people fighting poor, parents battling their teenagers, and wives in conflict with their husbands.

The publisher said the 480-page novel will be sold as an e-book and audio download as well as in traditional hardback form.

Rowling's seven Harry Potter novels have sold 450 million copies and have been translated into 74 languages. Her final Potter offering, "Harry Potter and the Deathly Hallows," was published in 2007. She published a short Potter spin-off collection of stories, "The Tales Of Beedle The Bard," in 2008.

The author said earlier this year she wanted to reach an adult audience, but kept the book's name and publication date secret until Thursday.