Just in time for Halloween comes the pleasurably creepy debut novel “In the Midst of the Sea: A Novel of Paranormal Horror” (Pace Press, 2019), set on off-season Martha’s Vineyard.

“Both the Cape and the Islands are so full of history, culture and time, that I almost feel like you can’t help but feel the ghosts around you,” author Sean Padraic McCarthy of South Plymouth said in an email interview last week. McCarthy has spent time on Martha’s Vineyard over the years, and he says that creating that weird and desolate off-season atmosphere was one of the challenges he faced in writing the book. “The ghost tours out there are great,” he adds about the Vineyard.

McCarthy grew up in Abington on the South Shore, one of seven children. His parents were both school teachers and some of McCarthy’s earliest memories revolve around accompanying his parents to the local library. “They both always had a pile of books on their nightstands,” he recalls. “I had, for a long time, written poems and song lyrics and dialogues—I even started a terrible novel in high school.”

McCarthy went on to earn his master’s degree in writing at the University of San Francisco, lived for a time in Bermuda, and then settled back in Massachusetts. He married and became a father of six. “I write daily, but I’m not a full-time writer; I’ve worked for the department of mental health as a human service coordinator for years,” he says.

McCarthy’s plot setup is a strong one. It’s 1994. Diana, 24, and her slightly older husband Ford are living in a house built in 1871 in the Methodist Campground in Oak Bluffs. Ford inherited the house from his 95-year-old aunt Dorothy Evelyn Barlow. Although the pair have been married for just a year and a half, the marriage is troubled. Also present is Diana’s daughter Samantha, born of a previous liaison. Like McCarthy, both Diana and Ford come from large families. Diana is an unemployed nurse while Ford works the night shift at local post office.

The plot gets moving when Samantha finds, in the basement, a journal kept by Elizabeth Veronica Steebe. The first entry was written on June 16, 1871, and the journal covers Elizabeth’s life with her devout husband Hiram through May 8, 1872. Elizabeth is apparently the same person with whom Samantha has been holding imaginary conversations as she plays with the creepy antique dolls left in the house.

And let’s not forget to mention that the creepy basement contains a well. If you drop a penny down in the well, you’ll hear it clink way, way down in the water that’s at the bottom of the well.

Let’s also not forget that the macho Ford will no longer go down into that basement due to an experience he had there when he was making a stand for his telescope. Ford heard whispering.

McCarthy is an accomplished writer of short stories. His fiction has appeared in numerous periodicals such as Glimmer Train, Supernatural Tales and The Sewanee Review. His story “Better Man” was listed as a “Distinguished Story” in the “Best American Short Stories 2015” collection. In 2016 he was a recipient of the Massachusetts Cultural Council’s Artist Fellowship in Fiction Award.

Steebe’s journal begins in 1871. To create a feeling for that time period took research on the Methodist Camp Meeting Association and the building of Cottage City, or Oak Bluffs. McCarthy also looked into the building of the old hotels and the clashes that occurred as Oak Bluffs began to develop into a tourist destination. “I also spent some time researching the 19^th century spiritualist movement—I’ve always been interested in books on that subject an era—and on Paschal Beverly Randolph,” he says.

Randolph was an African American doctor, occultist, spiritualist, trance medium and writer who lived from 1825 to 1875 and died of a wound to the head under mysterious circumstances. As her own life is spiraling out of control, Diana meets Randolph, who is using an assumed name. At one point he tells her that “there are ghosts all over the island. Houses, landscapes, the reflection in the eyes of the gulls on the beach.” As things get creepier, and it becomes harder for Diana to tell the living from the dead, Randolph also explains “paranormal imprints,” which differ from ghosts in that they’re “residual high energy, often left behind.” “Imprints” are everywhere—“maybe we’re often seeing people who aren’t really there, passing them on the street, but we don’t realize it.”

Diana is surrounded by the living and the dead. Will Diana be able to save herself and her little girl from the horror that seeks to engulf them both? As the days grow shorter, and you find yourself in the mood for something really chilling, try “In the Midst of the Sea.” McCarthy will sign copies of his novel on Saturday, Oct. 12 beginning at noon at Yellow Umbrella Books in Chatham. For more information call the bookstore at 508-945-0144.