John Grisham is trying something truly different. Grisham, better known as the master of the legal thriller, has sold millions and generated movies from his suspenseful books about lawyers and the American justice system.

With such extremely popular books as 1989’s “A Time to Kill” and 1998’s “The Firm,” he drew a wide following via a familiar formula. But shortly after the well-written, partly autobiographical 2001’s
“A Painted House,” Grisham began doing something unusual.

He wrote more obviously complicated, textured novels about subjects he had previously tackled, beginning with 2008’s “The Appeal” all the way to 2016’s “The Whistler.”

Grisham was clearly veering more and more away from the structure and style he was known for.

He now has strayed farthest from formula with his latest book and 31st novel, “Camino Island” (Doubleday, New York, 2017, 290 pages). Stylistically and thematically, this book is a departure from his usual oeuvre, to the point where it is almost unrecognizable as a John Grisham thriller.

That isn’t to say “Camino Island” is without merit—far from it. Technically, it belongs to another subgenre—the bookstore mystery. These are thrillers set in bookshops, or which feature owners or regulars from bookshops, the central plot with the bookselling or publishing industry in the background.

It’s actually an enjoyable, popular genre. The most well-received series in this niche is John Dunning’s Cliff Janeway series, which features the titular character, a bookstore owner who inevitably gets pulled into solving crimes.

Grisham makes a great contribution to the subgenre. “Camino Island” begins with an audacious crime. In a daring, creative heist, five men steal five handwritten manuscripts by F. Scott Fitzgerald from Princeton University’s Firestone Library. The original plans get all mixed up, and the manuscripts vanish.

Broke and unemployed

Then a wealthy, powerful insurance company hatches a plan to get the manuscripts back. The firm hires a lapsed, broke and unemployed fictionist named Mercer Mann to go to the fictional Camino Island in Florida. She is to befriend the man who is believed to have the manuscripts, a roguish bookstore owner named Bruce Cable.

This becomes complicated when Mann finds herself utterly charmed by Cable, and soon, she becomes conflicted between her feelings for Cable and her commitment to finding the manuscripts.

Grisham takes his time describing Camino Island and its strangely large number of writers past and present. He also patiently and exhaustively talks about the challenge of running a bookstore.

Then “Camino Island” touches on the mysterious world of rare books, where fortunes can be exchanged for signed first editions and even more money can be made from stolen handwritten manuscripts.

For lovers of books and book-related books, “Camino Island” is an efficient, effervescent piece of work. Unlike most of Grisham’s work, “Camino Island” starts furiously and then slows down to a crawl for most of the pages, just raising its head and striking very close to the end.

Because of that, save for the enigmatic Cable and the torn Mann, the characters in the utterly straightforward “Camino Island” are predictable and hew to type. There’s not much menace here, leaving only those who care about writing and bookselling to care about what happens and how it all ends.

It also stands as a clear product of Grisham’s move toward redefining what he’s known for.

Grisham fans may find themselves utterly befuddled by this breezy, friendly book, but in many ways “Camino Island” is Grisham’s love letter to his field, and ultimately a very rare one, as he essentially stated that his next book will be another legal thriller.

In the meantime, “Camino Island,” a book about books, is a cool and unusual change for John Grisham, a refreshing taste of something really different from an anticipated artisan of the expected.

Available in hardcover edition at National Book Store