When 16-year-old Shane Carter’s disfigured body is found hanging by its tied hands at a re-created 17th-century village in the fictional Midcoast Maine town of Granite Harbor, a novice detective is tasked with finding the killer.

“Granite Harbor,” by Peter Nichols. Celadon Books. $29

Detective Alex Brangwen is an ex-pat Brit who had success as a young novelist in the United Kingdom, but was persuaded by his now ex-wife Morgana to move to Maine: “You’ll love it there. It’s full of writers.”

When his writing career lagged, Brangwen became a Granite Harbor policeman to get a steady paycheck; Peter Nichols’ new thriller takes its title from the hitherto peaceful, small town. Now, Brangwen faces intense pressure from townspeople to uncover the killer before another gruesome murder takes place.

The imperious Morgana is from a wealthy Texas family. She and Alex share custody of Sophie, their teen daughter, who was close friends with the murdered boy, as well as Jared and Ethan, his best pals, who might be suspects – or might be targets. Increasingly frustrated with Sophie’s growing independence, Morgana insists that Alex intervene when the two are at loggerheads. She also leads demands that the investigation go more quickly.

Locals who work as “players” at the living history settlement museum figure prominently in the thriller, including Isabel, Ethan’s mom and a former love interest of the detective; and Roger Priestly, who plays the Apothecary, an important figure in colonial life who dispensed herbal “nostrums and electuaries” and served as a pseudo doctor. Nichols’ research on history and botanicals, is impressive, and biology and chemistry will turn out to play important roles in Brangwen’s investigation.

As the book unfolds, the characters emerge clearly. Nichols paints realistic pictures of the lives of town citizens; the relationships between parents (especially mothers) and their children; and the tightrope that teens walk between childhood and adulthood. He also writes about the town itself without resorting to stereotype. As an aside, if you lives in the Midcoast, as I do, you’ll have no trouble guessing which real town Nichols used as his model for Granite Harbor.

Brangwen begins interviewing townspeople, while his boss, Police Chief Billie Raintree, asks for help from the FBI. At Raintree’s request, Special Agent Harris is sent from Boston and attends the autopsy of the murdered boy in Augusta. But the results of the autopsy only complicate the case. 

Agent Harris’s FBI research reveals that a frighteningly similar murder — a young man, same disfigurement, same display — occurred 16 years earlier at Prout’s Neck. He concludes that a serial killer lives in Granite Harbor. It feels a tad implausible that townspeople wouldn’t remember the earlier murder themselves, but Nichols’ plot device helps feed the tension between the investigators.

About one-third of the way into “Granite Harbor,” the unnamed killer appears, and Nichols commences alternate storytelling. On one track, Detective Brangwen and Agent Harris search for evidence. On the other, the predator grows up as a neglected child, abused orphan, and bullied and ultimately sinister teen.

Agent Harris, cocksure that the Bureau’s methods of profiling will lead them to the killer, confidently identifies suspects. But Chief Raintree believes profiling “is no better than astrology.” Brangwen, meanwhile, follows bits of chemical information provided by a University of Maine lab to their logical, but not necessarily correct conclusions, while the teenagers do what they do in horror movies — put themselves needlessly at risk.

The two storylines move ever closer toward an eruption. What will come first, a break in the case or the next murder?

In the acknowledgments, Nichols thanks his editors for trimming his novel, saying: “. . . it went from sprawling forest to neatly trimmed bonsai.” That shows. The chapters are short, with crisp endings, and the action is brisk. Step by step, the propulsive novel marches toward a reckoning. Nichols drops clues but camouflages them so cleverly that they are easy to miss. When the storylines do suddenly collide, it makes for a surprising and satisfying resolution to the murders, after which the residents of Granite Harbor begin to piece together their lives.

Dewey Meteer is a retired naval officer. He lives in Nobleboro.