NO MORTAL REASON, by Kathy Lynn Emerson, Pemberley Press, Corono Del Mar, Calif., 275 pages, paperback, $17.95

The only problem with “No Mortal Reason,” Kathy Lynn Emerson’s third installment in her Diana Spaulding mystery series, is that it’s not set in Maine. Emerson three years ago introduced her late 19th century heroine, a reporter for a New York newspaper, in “Deadlier than the Pen.”

In that novel, Diana Spaulding traveled to Bangor by train during a blizzard in search of a killer only to find true love with Dr. Ben Northcote. Since then, he has followed her to Colorado where the reporter reconnected with her estranged parents in “Fatal as a Fallen Woman.” That book had her interviewing prostitutes and visiting mining camps.

The latest novel finds them 125 miles north of New York City so that Diana can meet for the first time her aunts, uncles and cousins and introduce them to her fiance before the couple returns to Bangor, where they are to be married. Before the reporter can introduce herself, however, she must report on and help solve two grisly murders.

The family owns a hotel that is undergoing extensive renovations in hopes that the sleepy town will become the next Saratoga Springs – a thriving resort popular in the late 19th century for its curative hot springs. While Emerson’s fans in other parts of the country may enjoy Diana and Ben’s gallivanting, Maine readers simply want to shake them and shout, “Go home already and stay put!”

There must be plenty of mysteries to solve and patients that need the services of Dr. Ben in the Queen City. And New Yorkers must have been as enthralled then as they are now by the antics of summer people on Mount Desert Island.

While Lenape Springs, the setting of “No Mortal Reason,” might not be familiar to Maine readers, it is home to Emerson and based on the town of Liberty, N.Y., where she grew up. In her author’s note, she wrote that many of the details about the fictional setting she found in the memoirs of her maternal grandfather, John Gorton, who was born in 1878.

It’s those details that make Emerson’s books such a joy to read. She does not bog readers down with details, but gives just enough so they can picture not only the setting her characters find themselves in, but also what daily life was like in the 1880s. Emerson does not skimp on the hardships of travel or the status of women at a time when they were considered property of their fathers and husbands.

“No Mortal Reason” focuses more on family issues than the previous two books did, so the action moves a bit more slowly. The characters in Lenape Springs are a bit sedate compared to the prostitutes, miners, actors and cigar-champing editors that populated the earlier novels.

Diana and Ben need to get back to Bangor, where his mother, a grande dame so far unequaled in the series, and mentally ill brother await their return. Readers can only hope that more blood than champagne will be flowing at their wedding so the intrepid reporter continues to be torn between her career and her man. That tension is what keeps readers coming back.