The mystery is fundamentally moral at its heart. Whether the tale is about a real heart pounding beneath the floorboards (happy 200th birthday, Edgar) or a metaphorical one seeking justice, mysteries are all about right and wrong. My choices this month lurk in the area between.

THE RENEGADES

by T. Jefferson Parker (Dutton, $26.95, 352 pages)

Sheriff Charlie Hood is a righteous man -- a modern-day Wyatt Earp, patrolling the vast border between the United States and Mexico, between the law and lawlessness, between the trying-to-be-good and the very, very bad. On a routine patrol, Hood witnesses his partner being gunned down in the street. Everything about his partner "said honesty and goodness," but in Hood's world, no one is that wonderful, so he digs deeper. In a plot that gallops, Hood uncovers "murdered drug couriers, suspect deputies" and "mysterious piles of money." Parker's references to the Old West -- his gangs of outlaws vying for power, his landscape of Joshua trees, tumbleweeds and dirt roads -- create a morally complex thriller. Parker's characters, the good, the bad and the really nasty, operate with their own codes of honor in a moral borderland where chaos and opportunity are twins and sometimes there are only seconds to decide which is which.

AMONG THE MAD

by Jacqueline Winspear (Henry Holt, $25, 320 pages)

Winspear writes what I fondly call "Masterpiece Theatre" mysteries -- British mysteries of manners, highly evocative of place, often historical, with a compelling main character. Maisie Dobbs, a nurse during World War I, is a Cambridge-educated psychologist and a private investigator. Dobbs is intelligent, intuitive and empathetic (she could be Clarice Starling's prototype). Special Branch enlists her to create "a template" for the man threatening London with "a terror never before unleashed." Searching for his identity takes Dobbs into the asylums for the thousands of soldiers suffering from "soldier's heart." In a moving subplot, Billy Beale, Dobbs' stalwart assistant, struggles to help his wife, who is suffering from depression after the death of their infant daughter. This is the fifth novel in Winspear's accomplished series. Her recurring theme of the effects of class conflict and gender discrimination is incorporated into a larger moral one that resonates today -- when society discards those whose wounds we can't see, eventually we will pay a price. Winspear's overall tone is hopefulness, but it's bittersweet because we know what's on history's horizon.

A RULE AGAINST MURDER

by Louise Penny (Minotaur Books, $24.95, 336 pages)

"Something rancid and stinking and horrible" festers within the Finney family and it becomes chief inspector Armand Gamache of the Quebec Surete's job to excise it. Gamache is an undemonstrative poetry-loving detective in the tradition of Agatha Christie's Poirot and Ruth Rendell's Wexford. Because of a dark spot in his own family's history, Gamache understands that "spreading pain around doesn't lessen your own." Surprisingly, no murder occurs until 90 pages into this mystery, but in Penny's skilled literary hands, it doesn't matter. The setting, the Manoir Bellechasse, a legendary resort in the Quebec countryside, is thoroughly inviting. Gamache, his wife and the owner of the manor are all genuinely interesting. Plus the secrets of the inn's reclusive chef, her waitstaff and all the festering Finneys offer enough intrigue that when the murder does occur, I had everything I needed to assist Gamache in his investigation.

BONES OF BETRAYAL

by Jefferson Bass (Harper Collins, $24.99, 368 pages)

If you're pining for the understated humor and genial patriarchy of "CSI's" Gil Grissom, this book's main character, Bill Brockton, may hold your melancholy at bay for a few hours. Brockton is a forensic anthropologist searching for the link between a dead scientist in the present and a dead journalist from the past. Jefferson Bass is actually the pseudonym for two writers: one a scientist who founded the University of Tennessee's Body Farm (literally a farm where bodies are cultivated for forensic study, and the setting of the novel), and the second a journalist. This partnership of science and writing is a weakness and a strength. On the one set of eight carpals, five metacarpals and 14 phalanges, at times I felt as if I was reading notes from a Biology 101 lecture. On the other hand, the forensic details build a solid backbone for the story's suspense. When clues point Brockton to the Manhattan Project of the 1940s, the only link to the dead scientist is his ex-wife, Beatrice, a funny, feisty old woman. Beatrice's narration adds flesh to the "bones of betrayal" and life to the novel.

LOST RIVER

by David Fulmer (Houghton Mifflin, $25, 352 pages)

Set in the "scarlet streets" of Storyville, New Orleans' red-light district, in 1913, Fulmer's mystery may be a good choice if James Lee Burke's novels are too violent for your taste. Storyville's livelihood is based on "an economy of sin" where there's "something for every pocketbook," and where everyone is getting rich off the backs of women. When customers are murdered, their bodies dumped on the stoops of the bordellos, the district's madams ask Creole detective Valentin St. Cyr to find the killer. Like Sherlock Holmes, St. Cyr recruits street urchins as his eyes and ears, and, like Holmes, St. Cyr is struggling with his own demons. St. Cyr carefully builds a case that turns out to be more complicated and more personal than he thought. The atmosphere Fulmer creates is rich, nuanced and authentic. You can smell the gumbo of "sour rot, rust, smoke, and sweat," and you can hear the parlor pianos, the "rough jass and gutbucket tunes" echoing from the saloons.

Carole Barrowman is a professor of English at Alverno College in Milwaukee. She blogs at www.carolebarrowman.com/