A long-lost Sherlock Holmes story surfaces. But is it for real?

Call it a riddle wrapped in a mystery inside an enigma: A long-lost Sherlock Holmes mystery has been discovered in an attic in Scotland where it had been forgotten for decades. The question: Is the author of this missing mystery Sir Arthur Conan Doyle? 

The story itself is an unsigned 1,300-word tale dating to 1903 entitled "Sherlock Holmes: Discovering the Border Burghs and, by deduction, the Brig Bazaar."

Historian Walter Elliot had owned the book for "40 or 50 years," so long, he told The Telegraph he'd forgotten how he’d acquired it.

The story begins with a journalist looking for Holmes in London to get a quote. He finds the detective urging Watson to take a trip to Edinburgh with him to solve the "mysteries of the Secret Cabinet." Problem is, Watson declines to join the journey. Why? Holmes uses his deductive skills to guess where Watson is going instead – "to Selkirk in aide of a Bridge," a reference to the purpose for the story's publication – part of a fundraising effort to repair a bridge in Selkirk, Scotland.

The yarn was originally published in a small collection, “The Book o’ the Brig,” which was sold at a benefit bazaar to raise money for a bridge in Selkirk, Scotland.

The bridge is once again to be replaced, which prompted Elliot to offer the long lost story as part of a pop-up museum in the town.

But is it actually a Conan Doyle mystery?

Elliot, the historian who discovered the story, has firmly stated his belief that Conan Doyle himself wrote the story. “I’m not a specialist, but the vocabulary seems pretty close to the way Conan Doyle wrote. I’m fairly sure it was written by him," he told the UK's Guardian.

But as soon as the story came to light, doubts were raised about its authorship.

"Swedish writer and Holmes expert Mattias Boström noted that there’s no mention in advertisements and bazaar records of Conan Doyle contributing an original piece, and other fans have argued that the flowery, ornate style of the prose does not resemble Conan Doyle’s action-oriented, concise style," reported the Huffington Post.

Nor does it "feature the detached, cold Holmes or sharp, precise deduction of the detective's more famous tales."

It's possible Conan Doyle wrote the piece as more of a lighthearted spoof of his more serious work, as a way to help Selkirk raise money for its bridge.

Or, it's possible Conan Doyle is not the author.

Surprisingly, it may matter little to Sherlock Holmes fans. From Benedict Cumberbatch’s "Sherlock" and Robert Downey, Jr.'s "Sherlock Holmes," to CBS's "Elementary," and a number of Holmes-related titles, interest in Sherlock Holmes-style gumshoe has swelled in recent years, and fans are lapping it up.

A long-lost, unsigned Sherlock Holmes story discovered decades after it was first published – and that is a mystery in and of itself? For Sherlock Holmes fans, whether or not Conan Doyle penned the story, the mystery of it all may only deepen the enjoyment.