Dianne K. Salerni made herself an open book last week, dishing about the stories behind her stories. More will be revealed when she stops by the Hockessin Bookshelf on Sunday, Sept. 7.

Next Sunday, the Hockessin Bookshelf will spend the afternoon with Dianne K. Salerni. A teacher-turned-author, Salerni has deep roots in Delaware, having graduated from St. Marks High School before going on to study elementary education at the University of Delaware.

She has three books under her belt now and her experiences, from the geography that she calls home to inside family jokes, help shape the mysteries she often writes about. Always a teacher at heart, she researches her subjects extensively before putting pen to paper (or finger to keyboard) and the reader might even accidentally learn a thing or two while reading.

Salerni made herself an open book last week and dished about the stories behind her stories.

Q. “The Eighth Day” is your most recent book. Can you explain the premise?

A. In “The Eighth Day,” a boy discovers an extra day hidden between Wednesday and Thursday and a girl living in the house next door who exists only on that secret day. It’s been compared to the “Percy Jackson” books because it’s set in contemporary America and draws on King Arthur legends the same way the ‘Percy’ books draw on Greek mythology—although, I never read any of the ‘Percy’ books until after I’d signed the deal for ‘The Eighth Day.’

Q. What was the inspiration for the “extra day,” though?

A. It was a family joke between my husband and my daughters. Whenever they bugged him about wanting to do something—go to Hershey Park, go to the beach, go ice-skating—he teased them by saying they could do it on ‘Grunsday.’ I started imagining what it would be like if there really was a Grunsday, but only certain people experienced it. Then, while researching legends about extra time and suspended time, I stumbled across a story about Merlin that intrigued me. The next thing I knew, I was weaving legends of Arthur and Merlin into the origin of the secret eighth day.

Q. Your second book, “The Caged Graves” is set in Catawassa, Penn., a relatively short two-hour drive from your home in West Grove. Does the area mean something to you?

A. I saw a photograph of a caged grave on the internet while I was researching ghost stories of the Pocono Mountain region for another project. I was fascinated and enthralled by the picture. With the help of my husband and Google Earth, I pinpointed the location of the cemetery outside Catawissa. It was only an hour away from a vacation house my family owns in the mountains, so the next time we went skiing, we drove the long way home, by way of the cemetery. Not only did we find the caged grave from the photo, we discovered there were two of them. That’s when I knew I was going to write a book about those graves. One caged grave is weird. Two is a story.

Q. It sounds like you do a lot of research.

A. Yes, tons of research! That means reading biographies, non-fiction accounts, and even historical fiction set in the same time period, just to get a feel for the details. In ‘We Hear the Dead,’ historical letters from the real Maggie and Kate Fox helped me pin down the voices of my characters. While working on ‘The Caged Graves,’ my editor challenged me on a cupcake reference, and I had to prove cupcakes were popular in the 1860s. I often write my first draft “by the seat of my pants,” and random bits of research can divert the whole story – which is why ‘The Eighth Day’ ended up delving into Arthurian legends. For that book, my husband also flew us both to Mexico so I could climb the Pyramid of the Sun and physically plot out the climactic scene where the bad guy tries to destroy the regular seven days of the week. Research can be a lot of fun, and I never know where it might take the story.

Q. Your first book, “We Hear the Dead,” inspired a short film that premiered at the Cannes Film Festival. Did the filmmakers do the story justice?

A. I’m actually impressed at how much of the premise the director and producer were able to convey in a seven-minute story line: three sisters run a séance scam, although one of the girls has more paranormal talent than the other two realize.

In my book, Maggie and Kate Fox are teenage girls but the movie portrays them as young women in their twenties. But that was for practical reasons, to avoid hiring minors in the lead roles. However, ‘The Spirit Game’ is now being pitched as the premise for a possible television series, with the girls’ ages closer to the characters in my book.