It's Black Friday, the official beginning of the Christmas shopping season in downtown Bethlehem. The city is festive. Merchants are ringing up record profits.

Then … one of those shopkeepers is murdered in a mysterious fashion.

Thus begins Larry L. Deibert's latest novel, "The Christmas City Vampire."

Deibert signs copies of his book, 1 - 3 p.m. March 3 for "Local Author Sundays" at the Moravian Book Shop, 428 Main St., Bethlehem.

This is Deibert's third or fourth novel, depending on how you count.

His third, "Combat Boots, Dainty Feet" is an extensive rewrite of his first, "95 Bravo." Deibert, a Vietnam veteran, used Vietnam as the setting for both.

"I like to involve my characters in places I've been," he explains.

Deibert has done that in "The Christmas City Vampire." Local readers will instantly recognize the setting and the frequent references to local landmarks like the Bethlehem Brew Works, the Lehigh Valley Mall and the Sands Casino Resort Bethlehem.

The juxtaposition of familiarity and alien evil is intriguing.

He also tries to insert his children (anonymously, of course) into everything he writes.

Deibert, a retired U.S. Postal Service mail carrier, grew up in the Lehigh Valley and has lived in Lower Saucon Township with his second wife since 2002. Deibert retired from the postal service in 2008, and two days later went to work as a courier at Lehigh Valley Hospital, where he still works.

His experience as an author offers a window not only into how some writers work, but also into the dramatic advances in the publishing trade that benefit unknown authors like him.

Deibert talks about how sometimes, as he's writing, "The characters would seem to pop up from nowhere.

"A lot of writers start out with an outline and a list of characters," he says. "I could never do that." With "95 Bravo," he says, "About three chapters in, I knew how it was going to end."

His efforts to get published are easier in this internet age. "95 Bravo" was published as an e-book after being rejected by several print publishers.

"The Christmas City Vampire" was published by a small company, Bradley Publishing, which offers his book for sale as "print by demand." This route is less expensive for the publisher, which doesn't have to finance an extensive printing without knowing what the demand will be. So, it is easier for unknown writers to gain exposure.

The internet also makes editing a less expensive proposition for publishers, with editors who can work from home on copy that is emailed to them.

Deibert acknowledges that when he was young, he was never much of a reader, and never thought about writing until 1975, when his first wife was pregnant and it occurred to him that he should write about his life for his son.

He sent that first effort, which included some of his Vietnam experiences, to 23 different publishers with no success, "so I thought, 'maybe I'm not a writer'."

Then in 1990 he joined a veterans' group and began listening to their stories. Many were more compelling than his, since he spent most of his Vietnam service behind a desk, and one of those veterans suggested he rewrite his book, including some of their stories.

That was "95 Bravo."

Next was his first vampire book, "Requiem for a Vampire." He had wanted to write a vampire book because he had strong opinions about how the topic has been treated in other novels.

"I didn't think you could kill it [a vampire] with a stake through the heart," he says. He thinks you would have to separate its head from its body in order to destroy it.

After "Requiem," Deibert didn't do any writing for awhile. Then he heard about a contest online, challenging writers to produce a 50,000-word novel in 30 days.

At first he thought the task too daunting. Then he began thinking about a possible topic and came up with the idea of a murder mystery set in Bethlehem during the Christmas season.

He sat down and wrote 1,700 words the first day.

Deibert networks extensively with other writers. He contacts them through Vietnam veterans' groups, on facebook and through other social media. It helps, he says, to exchange books with other writers and get their feedback.

And while his creative muse was dormant before "The Christmas City Vampire," he is again brimming with ideas for manuscripts.

"I have four or five that I'm working on, in different stages."

One that he particularly wants to finish is a time-travel novel set in Gettysburg in 1863.

He was working on that one the day before this interview, and as he was writing, "something happened [in the book] that I totally didn't expect."

The hardest part, he says, is going back and editing and rewriting his original work.

Although not much of a reader when he was young, Deibert enjoys reading now, both fiction and nonfiction. He began to enjoy it while in the miltary service, when he had long periods of time with nothing to do.

Then he enjoyed reading to his son and daughter when they were young.