“At the Water's Edge,” by Sara Gruen. (Spiegel & Grau)

Kicking off a story with an unsympathetic character is tough; kicking off a story with three unsympathetic characters requires almost mythic power to succeed. Perhaps that’s what Sara Gruen was thinking when she devised a trio of spoiled New Yorkers high-tailing it to the shores of a dark Scottish lake in search of its most famous occupant.

That’s right: The author who drew attention to the plight of circus animals in “Water for Elephants” and bonobos in “Ape House” has put yet another creature at the heart of a book, a novel set during World War II.

Socialite Madeline Hyde’s father-in-law once searched for “Nessie,” but he was discredited. Now, her husband, Ellis, and his noisome guy-pal Hank decide to exploit their 4-F status — Ellis is colorblind, Hank is flat-footed — to redeem Col. Hyde’s failed mission and win the old man’s respect.

Soon, Maddie, Ellis and Hank are hunkered down in Drumnadrochit, a lakeside hamlet haunted by a dead infant and a suicide. Before we can say, “Where else did he hurt you, m’eudail?” (yes, there’s a man who talks like this), we meet Willie the Postie; a woman everyone calls Mhàthair; fiery redheaded Meg; and Anna, the inn’s housekeeper, who steeps the (rationed) tea longer if she likes you.

These characters come straight from “The Big Book of Gaelic Bodice Rippers,” and events move several laces down the corset as one woman winds up the victim of domestic violence, another faces forbidden love and everyone’s equilibrium is tried by the unpredictable peregrinations of Ellis and Hank. This unpleasant pair disappears for weeks at a time. What’s a bored young socialite wife to do except learn to cook and clean and keep her prescription opiates as hidden as possible?

Gruen does have deeper themes in mind, and occasionally they break through. At one point after Ellis has been verbally abusive, Maddie thinks, “I . . . hoped that Ellis would find the monster . . . and that it would have the curative effect he was so sure it would, because if it didn’t, I couldn’t shake the feeling that I’d just had a glimpse of the future.” As Maddie approaches a breakdown and Ellis and Hank risk a scandal, the whole population of Drumnadrochit waits for war to end and life to return to its old rhythms.

While fans of Diana Gabaldon’s “Outlander” novels may adore the Scottish hunk who tempts the girl, many readers will find the story’s ultimate mystery cloudier than Loch Ness, and they’ll be even more disappointed that it has nothing to do with an aquatic monster.

Patrick is a writer and critic who tweets @thebookmaven.

AT THE WATER’S EDGE

By Sara Gruen

Spiegel & Grau. 354 pp. $28