This is a mystery novel worth staying home for: Cancel those weekend plans, crank up the air conditioner and mute all electronic devices. You’ll want plenty of silence and slow time to savor “How the Light Gets In,” the ninth novel in Louise Penny’s extraordinary series starring Chief Inspector Armand Gamache and his troubled sidekick, Inspector Jean-Guy Beauvoir, of the Surete du Quebec. “How the Light Gets In” is the culmination of a story arc that has been developing over the most recent books; happily, it is not the termination of the series.

Carrying forward the tradition of mystery masters such as G.K. Chesterton and Dorothy Sayers, Penny has been working throughout her series to tap into the spiritual dimensions of the genre. Her formula for the Gamache mysteries has evolved into one part foul play, two parts morality play. Occasionally, Penny overdoes the theologizing (as in “The Beautiful Mystery,” last summer’s somewhat sluggish Gamache adventure set in a remote monastery). In “How the Light Gets In,” however, she gets her proportions just right: There’s an epic conspiracy at the center of this tale — a battle between the forces of good and evil — the likes of which hasn’t been seen since the heavenly army faced off with Lucifer’s fallen angels in “Paradise Lost.”

As Penny explains in her poignant acknowledgments, this novel’s title is taken from a Leonard Cohen song called “Anthem”: “There’s a crack in everything. / That’s how the light gets in.” When the story begins, many things are cracked indeed, foremost among them the once-close relationship between Gamache and Beauvoir. For 15 years they worked together — mentor to student, father to son — until a horrific shootout destroyed their bond of trust. Now, Beauvoir has gone over to the dark side: He has transferred into the command of Gamache’s arch-rival, Chief Superintendent Francoeur, a manipulator who’s never met a scruple he couldn’t ignore. Francoeur is intent on taking over control of the Surete, but only as the first step in a far-reaching, more nefarious plan that Gamache and a skeleton crew of loyal police allies are working furiously to comprehend.

Less cosmic puzzles also demand Gamache’s attention: In a small house in Quebec, an elderly woman is found murdered. She turns out to be the last surviving member of the Ouellet quintuplets, five sisters who had been born in the pre-fertility-drug era of the Great Depression. (Penny lifts liberally here from the grotesque real-life story of the Dionne quintuplets, whose parents ceded custody of their daughters to the government of Ontario, which then made millions off the sisters as a tourist attraction.) Another narrative thread involves the possible suicide of a middle-aged government worker who appears to have jumped off a bridge to her death. All these events, as you might expect, turn out to be connected.

What a reader can’t anticipate, however, is the outcome of the titanic contest between the bloody-but-unbowed Gamache and the cunning Francoeur, who’s stacked the Surete with his minions. The apocalyptic clash between the forces of the two men takes place in the isolated village of Three Pines (the setting of some previous Gamache adventures). Three Pines is an Internet “dead zone,” a settlement out of time, consisting of a few houses and stores and a high population of eccentrics. It is there, in the middle of the snowy woods, dark and deep, that a quick moment of grace happens.

Penny’s voice — occasionally amused, yet curiously formal — is what makes the world of her novels plausible. I can think of few other writers who could sidestep cuteness in a scene that features an elderly female poet and her pet duck. Gamache is our fixed moral center as always, but one who is increasingly bedeviled by doubts. During a potentially violent confrontation in police headquarters, he realizes he has been completely ostracized by the officers around him. We’re told:

“Armand Gamache had always held unfashionable beliefs. He believed that light would banish the shadows. . . . He believed that evil had its limits. But looking at the young men and women staring at him now, who’d seen something terrible about to happen and had done nothing, Chief Inspector Gamache wondered if he could have been wrong all this time. Maybe the darkness sometimes won. Maybe evil had no limits.”

Gamache — and Penny — clearly respect the power of evil too much to ask these questions merely rhetorically. Mysteries usually are heralded as an intellectual genre. (It’s not for nothing, after all, that Edgar Allan Poe called his stories “tales of ratiocination.”) In “How the Light Gets In,” Penny has written a magnificent mystery novel that appeals not only to the head, but also to the heart and soul.

Corrigan, who is the book critic for the NPR program “Fresh Air,” teaches literature at Georgetown University.


By Louise Penny

Minotaur. 405 pp. $25.99