It’s mystery No. 14 in Sarah Graves’ “A Home Repair is Homicide” series, and fans of the prolific Eastport writer will find surprises in “Knockdown.”

For one, it’s darker than the usual Graves cozy in which kidnappings and murder happen with no graphic description of blood and gore. By contrast, “Knockdown” introduces a weird young psychopath who arrives in peaceful Eastport with sharp tools for torturing the mystery’s main character — amateur sleuth and home repair expert Jacobia Tiptree.

To be fair to the book, its villain doesn’t get to use the worst of his implements. But fire, imprisonment and pain confront Tiptree in “Knockdown.” Some events at the book’s end resemble those in Edgar Allan Poe’s creepy 19th-century thriller, “The Fall of the House of Usher.”

Grave’s mystery opens on a sunny weekend early in July. “Jake” Tiptree is happily engaged in her usual hobby, this time scraping peeled paint off the porch steps of her big 1823 Eastport home. Meanwhile, a bicycle passes on the adjacent road — not once, but several times.

Same bicycle, same rider.

“And each time he went by,” writes Graves, “he’d been staring at her in that same unpleasant, almost accusing way. The bike was a balloon-tired Schwinn from the fleet of them that were available for rent downtown, with a wire basket up front, fake-leather saddlebags, and a bell.”

Something about the rider, a dark-haired man in his 20s with a blue-and-white polo shirt, strikes Tiptree as eerily familiar.

“Brring,” goes the man’s bicycle bell. “She wouldn’t have thought a bike bell could be rung threateningly,” writes Graves, “but he managed it.”

In the first few pages, Graves brings us up to speed on Tiptree’s past. She’s a New York transplant who settled in Eastport a dozen years ago. In her former life, she was unhappily married to a New York brain surgeon. Her job back then was managing money for mob figures.

In “Knockdown,” Tiptree’s former life as a money launderer comes back to haunt her in the unlikely form of bike rider Steven Garner Jr.

There’s a lot to like in “Knockdown.” Garner is a memorable, if slightly ridiculous, villain. He has a fetish about washing his hands, and likes to wear his deceased mother’s clothes. His ears stick out abnormally far and, fearing too easy identification by police, he glues them to his head.

Old house buffs and would-be old house owners will enjoy the contents of italicized boxes at the start of most chapters. Called “Tiptree’s Tips,” they’re slightly humorous snippets of home repair advice.

“Use whitening toothpaste and a soft toothbrush to clean stained counter-tile grout,” Graves tells readers via Ms. Tiptree. In another interesting chapter starter, the author suggests removing dents from a wood floor by “placing a clean, damp cloth over the dent and touching it repeatedly with a steam iron.”

A downside to “Knockdown” is a storyline that strikes one as implausible even in fiction. Bad guy Garner with the stick-out ears, for instance, happens to find a Canadian tourist in Eastport with the same kind of ears. Garner hires the man to confess to a crime Garner committed.

Like her main character, Graves owns a rambling 1823 house in Eastport, where she has lived since the mid-1990s. Her husband is a musician; she plays the five-string banjo.

Graves’ “Home Repair is Homicide” series has a national following.

Lloyd Ferriss is a writer and photographer who lives in Richmond.