Big Little Lies” meets “Rebecca” in Sarah Pinborough’s “Dead to Her,” a saucy novel about insecure second wives dragged down by secrets, jealousies and their struggles to fit in.

Pinborough, who is British, frequently sets her suspense novels in her home country, but after visiting Savannah, Ga., a few years ago, she sensed that the city’s Southern charm and sultry, heat-soaked atmosphere would be the perfect place to tell a story bubbling with sex, betrayal and dark turns. She was right.

For readers living in colder climates, basking in the balm of Savannah’s thick summer air is a much-appreciated escape, but so, too, is getting lost in the lives of Savannah’s poor little rich girls, Keisha Radford and Marcie Maddox.

The ravishing Keisha, 22, has just married the wealthy William Radford, a man 40 years her senior. She loathes him and asks herself daily why he can’t just die. A portrait of Eleanor, William’s dead, apparently perfect wife, still hangs in the Radford mansion, and all her possessions are devotedly cared for by her maid, Zelda, gothic Savannah’s answer to “Rebecca’s” Mrs. Danvers.

Like Keisha, Marcie was once a poor waitress, and she stole her older husband, Jason, from his first wife. These money-grubbing belles become ensnared in a snake pit of lies, abuse, drunken binges and illicit sex after Marcie suspects Keisha is trying to seduce Jason, who seems equally obsessed with Marcie’s luscious friend.

Most of Pinborough’s psychological thrillers, including her 2017 bestseller “Behind Her Eyes,” feature strong but unreliable female narrators. Keisha and Marcie fit the bill. As they narrate “Dead to Her,” we sense that at times they can’t tell fact from fiction. They’re spinning out of control, and we gleefully watch it happen.

The relationship between the drug-addled Keisha and the jealous, bent-on-revenge Marcie takes a shocking turn during a night of chemically induced misbehavior. If their explosive secret is discovered, their lives of luxury will implode. Soon they have more to worry about.

Keisha is a prime suspect when an attempt is made on William’s life, but so is Marcie, who may have decided the only way to keep Keisha away from her husband is to have Keisha arrested for the attempted murder of her own. Could Jason also be responsible because he’s been embezzling funds from William’s company?

Other suspects with other motives soon emerge. Pinborough does a nifty job of juggling possible killers, and even throws in a bit of black magic, hexes and conjure balls — a nod to Savannah’s voodoo subculture — to darken the novel’s mood even more.

It’s easy to hate Keisha, Marcie and the other high-society women in “Dead to Her,” and in one priceless scene a detective tells Marcie: “I don’t think I’ve ever worked a case where my problem was having too many suspects who could all easily be guilty. The issue I have is — and don’t take this personally — that you’re all such truly atrocious people.”

So true, but Pinborough lets us see the softer side of Keisha and Marcie, and we begin to care about them — until once again we don’t. This may not be the most important novel you’ll read this year, but it’s definitely among the most delicious.

Carol Memmott is a writer in Austin.

DEAD TO HER

By Sarah Pinborough

William Morrow, 400 pages, $27.99