BREAKING NEWS: “This Book Goes to 11!”—The story of Spinal Tap set to be released.giang

Just in case the sequel movie isn’t enough, This Is Spinal Tap fans are also being treated to a behind-the-scenes book this year!

It’s been over 40 years since the cult classic first hit screens, and director Rob Reiner — along with his Spinal Tap cowriters and costars Christopher Guest, Michael McKean and Harry Shearer — is telling the official (and firsthand!) story behind the 1984 mockumentary in written form.

A Fine Line Between Stupid and Clever: The Story of Spinal Tap will hit shelves in September 2025, timed to the release of sequel Spinal Tap II: The End Continues, publisher Gallery Books, an imprint of Simon & Schuster, announced on Wednesday, March 12.

In the original Spinal Tap film, director Reiner, 78, also played “director” Marty DiBergi, while Guest, 77, McKean, 77, and Shearer, 81, played the titular band: guitarist Nigel Tufnel, lead singer David St. Hubbins and bassist Derek Smalls, respectively. And, in the forthcoming book, the group “offers, for the first time, the full, unvarnished story of the classic film comedy’s creation, as told by the creators themselves,” Gallery Books said in a press release.

“In 1984, when This Is Spinal Tap was first released, no one could have imagined that it would become a cultural institution, as quotable as The Godfather (and arguably funnier) and worthy of inclusion in the Library of Congress’ National Film Registry,” per the publisher.

“Initially,” Gallery Books said, “every major studio turned it down. No one believed that Meathead from All in the Family [Reiner] had a future as a movie director. No one had ever heard of a mockumentary, much less, if you will, a rockumentary.”

So with no script (the dialogue was entirely improvised) to show, Reiner, Guest, McKean, and Shearer pushed onward, recruiting their pals for the film and composing Spinal Tap’s “Big Bottom” and “Stonehenge” — now-classics for the fictional British band.

“With wit and candor, without wigs and fake English accents, the authors [of A Fine Line Between Stupid and Clever] reveal the origins of their friendships, their creative process and their amazement in the film’s enduring afterlife,” Gallery Books said — just in time for the original film’s highly anticipated sequel.

And the book not only features insight from the men who brought Spinal Tap to life on-screen, but also some contributions from the rock legends who inspired their portrayal.

Slash of Guns N’ Roses, Rob Halford of Judas Priest, Don Henley of the Eagles, and Talking Heads members Chris Frantz and Tina Weymouth all make appearances, reflecting on how the 1984 film depicted the rockstar lifestyle — and sharing some of their own “Spinal Tap moments.”

A Fine Line Between Stupid and Clever will also feature a “B-side,” in which the foursome behind the book will tap (pun intended) back into their onscreen counterparts, Gallery Books promises.

“When you finish reading it, and flip the book over,” the publishers says, “you’ll find Smell the Book: The Oral History of Spinal Tap, in which Tap’s Nigel Tufnel, David St. Hubbins, and Derek Smalls recount their triumphs and travails to their dogged and somewhat weary interlocutor, director Marty DiBergi.”

Never miss a story — sign up for PEOPLE’s free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from celebrity news to compelling human interest stories. 

A Fine Line Between Stupid and Clever: The Story of Spinal Tap will be out September 2025, and is available for preorder now, wherever books are sold.