The publishing world has been abuzz this week with the news of the discovery of a second novel by Harper Lee more than 50 years since the publication of her first.

To Kill a Mockingbird was one of the most powerful, memorable books I read in my childhood, and I’m not alone by any means in having read and enjoyed it. The 1960 debut was wildly successful from the outset,earning Lee the Pulitzer Prize in 1961, and since then it has been translated into more than 40 languages, has sold in excess of 40million copies worldwide and has become one of the most important books in American literature.

In the past half-century, much has been written of the novel and its author, who frequently featured in lists of acclaimed authors who wrote only one novel, with the likes of Ralph Ellison (Invisible Man), Boris Pasternak (Dr Zhivago), Margaret Mitchell (Gone With the Wind), Emily Brontë (Wuthering Heights) and Sylvia Plath (The Bell Jar). But then came the announcement that another Lee manuscript had been discovered. Lee has said:

In the mid-1950s, I completed a novel called Go Set a Watchman. It features the character known as Scout as an adult woman and I thought it a pretty decent effort. My editor, who was taken by the flashbacks to Scout’s childhood, persuaded me to write a novel from the point of view of the young Scout. I was a first-time writer, so I did as I was told.

I hadn’t realized it had survived, so was surprised and delighted when my dear friend and lawyer Tonja Carter discovered it. After much thought and hesitation I shared it with a handful of people I trust and was pleased to hear that they considered it worthy of publication. I am humbled and amazed that this will now be published after all these years.

The reaction has been staggering. The Bookseller magazine described booksellers as ‘giddy’ at the news and reported a ‘trade frenzy’. According to Waterstones, the book will be ‘the most sure-fire hit of the century’. Its fiction buyer, Chris White, told The Bookseller: ‘I think if you were to come up with a wishlist of writers you most wanted to publish another book, there is nobody who would be above Harper Lee.’

And the readers’ reaction? Well, within 24 hours of the news breaking Go Set a Watchman had shot to the top of the Amazon bestseller list – all on preorders; the book will not be released until 14 July.

Although written in advance of To Kill a Mockingbird, the new novel is a sequel. According to the publisher’s statement, it is:

set in the fictional southern town of Maycomb during the mid-1950s, and sees Scout return from New York to visit her father, the lawyer Atticus Finch. She is forced to grapple with issues both personal and political as she tries to understand her father’s attitude toward society, and her own feelings about the place where she was born and spent her childhood.

Beyond the basic facts of the release, the media has been reporting all sorts of speculation, centered on the legitimacy of the discovery of the manuscript, and the ability of Harper Lee to make sound decisions given her health, which must be very difficult for the author to contend with. After all, it was her open distaste of publicity that led her to retire from public life in the early 1960s. She told an interviewer then that the reaction to To Kill a Mocking Bird was ‘just about as frightening as the quick, merciful death I’d expected … like being hit over the head and knocked cold’. I wonder what she makes of the media furore now. At least this time she could have expected it.

What stands out for me in this story is the courage of the author in releasing the book – she could have left it alone, and been content to be remembered as the writer of one of the most beloved and acclaimed books in American history. But instead, she has been true to her art, and gifted the world with another work. And certainly it is a gift – one for which people the world over are thankful.