After 15 years of marriage, Millicent and her husband are finding that life in the Florida suburbs is a little, well, dull. She's a real estate agent, he's the tennis pro at the local country club. They're not rolling in dough, but they're doing well enough in a nice subdivision while raising two teenagers, Rory and Jenna.
They have family dinners. And friends. And date nights. And a hobby. Their hobby is not like those of most other couples.
Millicent and her husband are serial killers. We know this in the earliest pages of the novel, so this revelation is no spoiler.
Their first murder is an accident, one orchestrated by Millicent's past, but an accident nonetheless. The second killing happens a bit more easily.
Then the real game begins. The couple meet on "date nights" to discuss prospects for their next victim. The husband (unnamed throughout his first-person narration) is the appointed hunter, seeking out strong but vulnerable women who match the couple's criteria. He does deep research, often meeting the women face-to-face under an assumed identity. He even sleeps with a few of them.
His wife, Millicent, likes the killing. She also likes secrets. We soon realize that she's enjoying this way too much and is keeping hubby in the dark about some very important details.
To throw the police off track, she begins following certain patterns of a dreaded, unconvicted serial killer who prowled the neighborhood almost 20 years before. Owen Oliver Riley, the terrifying boogeyman, snatched women off the streets, kept them captive for months and ultimately dumped their maimed bodies somewhere while taunting police and the press. His murderous spree plunged the Florida community into fear until he was arrested, tried on flimsy evidence, and released. The killings abruptly stopped.
The husband, originally not consulted on this rebirth-of-Owen idea, buys in to the ruse, even to the point of sending letters signed by the previous killer to the lead TV reporter following the new cases. Has the fiend from 20 years ago come back to his old haunts? How will he feel about being co-opted by these amateurs? Will their acts draw him out and put the copycat killers in danger?