On the left is a photo of Urquhart Castle above Loch Ness. The woman wearing the blue jacket in the center of the photo is me. I could not, alas, get Nessie [the Loch Ness monster] to make an appearance performing water ballet in the background.

My Jean Fairbairn/Alasdair Cameron mystery series explores the tension between legend and reality. Not that there’s anything wrong with legends, Jean would say. We use them to make sense of ourselves and our world.

Jean’s an American academic who fled a scandal back home and is now writing for a mild-mannered (she keeps insisting) Scottish history and travel magazine. Alasdair’s a burned-out Scottish police detective who says that legends go wrong when true believers refuse to recognize that they are legends—and even use them to justify crimes.

In The Murder Hole, Jean travels to Loch Ness to write about a stone carved by the mysterious ancient Picts, as well as to interview an American businessman intent on proving the existence of the Loch Ness monster. "Nessie," an enigma wrapped in a mystery wrapped in the Scottish tourist industry, is choice fodder for Jean’s magazine. Until one of Dempsey’s assistants is killed. Alasdair Cameron is on the case. And on Jean’s nerves, not altogether unpleasantly.

"Do you believe Nessie exists?" Jean asks him.

"I’m after keeping my fantasy compartmented," he replies.

To begin, there’s the sixth-century tale of St. Columba saving one of his followers from a loch monster. Taken in context, though, as Jean’s academic training has taught her to do, the tale is no more than a typical saintly miracle story.

A carved Pictish stone supposedly from the area-it’s been taken out of context as well-depicts a serpent-like creature. Is this Nessie? Or is it a snake? Who knows? And yet the Picts, while not the best known of Scotland’s ancient inhabitants, did exist.

Yetis might live in the isolated valleys of the Himalayas-the jury’s still out. The verdict is in on the coelacanth, a living fossil which has been found in the depths of the ocean. But Loch Ness is not a similar remote area. Most of the population of Scotland is a short drive away. Even before roads were carved through the Highlands, the loch itself was a highway. Victorians cruised to and fro and wrote poems about the landscape.

The sad truth is that no creature was reported in the loch until 1933, when a local man sent letters about cryptic sightings to the Inverness newspaper. Was he mistaken, was he mad, or was he deliberately committing fraud? No one can say for sure. I certainly can’t—in The Murder Hole I’ve created a new character with complex motivations to send those letters.

Of the millions of people who have visited Loch Ness since then, not one has taken a photo that is undisputedly of the monster. Expeditions have pulled every technological rabbit out of every technological hat, and not one has found definitive proof. Still, Nessie has been seen, over and over again.

Loch Ness is narrow, cold, and deep, and given to illusions of light and shadow, wind and mist. If seeing is believing, then when it comes to Nessie, believing is seeing. But as a good cop like Alasdair could tell you, eyewitnesses are notoriously unreliable.

None of this makes any difference to the lure of Nessie, just as the facts about any other popular Scottish legend—William Wallace comes to mind—leave the booming Scottish heritage industry largely unaffected. This is something that Jean finds amusing, even inspirational. Alasdair, on the other hand, is given to fits of "Bah, humbug" and mutters about Theme Park Scotland.

The Nessie industry is focused on Drumnadrochit. The town is just a couple of miles from where Urquhart Castle stands in picturesque ruins beside the loch. I remember when the Castle visitor center was a small portable building. Now Historic Scotland runs a huge visitor center that was carved out of the hillside, taking who knows what archaeological evidence with it. Yes, its construction was controversial. I myself heard a local boatman refer to Hysterical Scotland, even as he showed his passengers the many-times-copied sonar readings and underwater photos of blotches and blobs that are supposedly traces of Nessie.

The presentation at the Visitor Center emphasizes the real history of the area. As Jean notes, Historic Scotland has resisted the impulse to disney the place up with audio-animatronic clansmen and a Nessie running back and forth on an underwater track. Not so the village of Drumnadrochit. It is awash in fluorescent green Nessie souvenirs (why green?), most of which were made in China. There are gift shops, restaurants, tours, exhibitions, and a fiberglass Nessie floating in a small pond.

Nessie is not the only mysterious figure associated with the area. Aleister Crowley, the self-styled black magician, lived above the loch around 1900. If he had seen a mystifying creature  from his front porch, he’d surely have mentioned it, or even taken credit for its appearance. But in spite of his self-serving logorrhea, he said not a word about Nessie.

If Nessie is regarded fondly by the locals, Crowley is not. I found his biography in a gift shop in Drumnadrochit. When I presented it to the gentleman behind the cash register, he recoiled as though I’d offered him a grenade. There’s a lot of residual feeling in the area about Crowley, he said, both bad and good—and clearly his was bad. The real (as in real weird) character of Crowley provides a sub-plot in The Murder Hole, and my conversation with the shop owner led to another.

Do I personally believe in Nessie? No. But I certainly believe in mystery, and not just the ones in pages of books.