I began my year of “55 books at age 55” with an A: Alice I Have Been. So it’s fitting (and quite accidental, actually) that I end with a Z: The St. Zita Society by Ruth Rendell.

Rendell is a prolific writer; she’s published twenty-three Inspector Wexford detective stories as well as twenty-five stand-alone novels under her own name and another fourteen under the pseudonym Barbara Vine. All are mysteries and thrillers.

I’ve read books in all three lines, but only a handful (or two). After I’ve finished one, it’s enough for a while, because Rendell’s tales are intense, even petrifying—precisely because they seem entirely too plausible. Peeling back the layers of her maladapted characters’ psyches, she invites you to discover why these damaged souls behave they way they do, from the callously cruel to the deeply disturbed.

The St. Zita Society concerns an assortment of domestic helpers—a nanny, an au pair, a companion, a gardener, two drivers, etc.—who live and work in the posh London enclave of Hexam Place. St. Zita is the patron saint of maids and servants, and this group organizes in her name to gossip about their employers, hash over their grievances, and set in motion a series of mishaps and misery.

Rendell’s penetrating narrative reveals how deluded these characters are, as they peek behind curtains to construct warped versions of their neighbors’ motives and morals—and then act on those misperceptions. Although she works on a dark, depraved canvas, here Rendell actually had me thinking of Jane Austen. Both authors have that ability to paint individuals against the ground of their society; it’s just that Rendell’s vision is inverted, finding the worst instead of the best: tragedies, or nightmares, of manners.

As I finished The St. Zita Society, I kept wondering how often we—trapped inside our own systems of beliefs and prejudices—must misunderstand our fellow travelers in life. Not the happiest of notes on which to end my year’s reading odyssey, but an instructive one.