The theme of familial betrayal has been a part of literature since, well, forever. These two thrillers put a fresh spin on some of the oldest of tales.

At the beginning of The Better Sister by Alafair Burke, Chloe Taylor’s life seems like something out of the glossy pages of the iconic women’s magazine for which she is editor-in-chief. She’s at the top of her profession, her handsome husband Adam works for a white-shoe law firm, and their son, Ethan, is enrolled at a top Manhattan prep school. Chloe’s star rises even further when she edits a series of #MeToo stories about everyday women. Her success is the culmination of years of determination to leave behind an Ohio childhood marred by alcoholism and domestic violence. “In college, when other students scoured the catalogue for afternoon classes to accommodate their idiosyncratic sleep schedules, I was the one who set the alarm for seven so I could hit the gym and the commons before a 9:00 a.m. lecture,” she remembers at one point.

But beneath the surface, things are fracturing. There’s an affair. Ethan is caught with drugs. Chloe can’t log on to social media without encountering brutal anti-feminist comments. Oh, and Chloe’s troubled sister, Nicky—who is actually Ethan’s biological mom and Adam’s ex-wife—always lurks in the shadows, threatening to upend Chloe’s pristine image.

When someone breaks into their Hamptons home and murders Adam, Ethan becomes the prime suspect. Together, Chloe and Nicky must put aside the jealousy and pain of their past to save their son.

Burke was nominated for an Edgar Award for The Ex, and as a former lawyer, she ably weaves legal intrigue into her thrillers. The Better Sister is a brilliant look at the lengths a mother (or two) will go for family.

Samantha Downing’s My Lovely Wife has been described as “Dexter” meets Mr. & Mrs. Smith, but that doesn’t do justice to this deliciously deranged story. Think more Psycho meets “Desperate Housewives” meets Fatal Attraction.

Our nameless narrator is a tennis instructor at the posh local country club. His wife, Millicent, is a realtor. Nothing about their life is what it seems. They have a beautiful house in the tony Hidden Oaks neighborhood, but only because Millicent snagged it in foreclosure. Their relationship is based not on love and respect, but on a shared passion for kidnapping and killing women. Finding their next victim is the ultimate turn-on, making them feel they’re “wide awake while everyone else is asleep.”

Turns out, unbeknownst to her husband, Millicent is taking risks by keeping one of the women alive to torture her. When one of their victims turns up dead, it seems their pastime is about to be their undoing, until Millicent comes up with a plan to resurrect a long-gone local serial killer and pin the crimes on him. Owen Oliver Riley terrorized the community years earlier: “Two disappeared from inside their own homes. One was in a library, another in a park, and at least three had been in parking lots.”

When their actions start putting their own children at risk, one spouse is ready to pull the plug. But the other is all in. Dark and twisty, My Lovely Wife is a horrifying reminder that one never knows what keeps a marriage alive.