Psychiatrist Dr. Gwen Moore is an expert on killers. She’s spent a decade treating California’s most depraved predators and unlocking their motives - predators much like the notorious Bloody Heart serial killer, whose latest teenage victim escaped and then identified local high school teacher Randall Thompson as his captor. The case against Thompson as the Bloody Heart Killer is damning - and closed, as far as Gwen and the media are concerned. If not for one new development.

Sydney Shaw, like every single woman in New York, has terrible luck with dating. She’s seen it all: men who lie in their dating profile, men who stick her with the dinner bill, and worst of all, men who can't shut up about their mothers. But finally, she hits the jackpot. Her new boyfriend is utterly perfect. He's charming, handsome, and works as a doctor at a local hospital. Sydney is swept off her feet. Then the brutal murder of a young woman—the latest in a string of deaths across the coast—confounds police. The primary suspect? A mystery man who dates his victims before he kills them.

Joanne knows how lucky she is—Richard is a wonderful husband, Evie is the most gorgeous baby girl, they live in a beautiful house—life couldn't be better. But then Richard's twenty-year-old daughter Chloe turns up. Chloe hasn’t spoken to her father since the day he married Joanne two years ago. But with the arrival of her baby sister Evie, Chloe wants to make peace. Richard is delighted, and since Joanne is struggling with the new baby, he suggests Chloe could move in and help.

Socially awkward Chloe Cooper divides her time between dog walking, bartending, caring for her ailing mother, and at a safe distance, watching people and inventing the stories of their lives. Like Chloe’s new neighbors: glamorous influencer Jemma Spengler and Jemma’s husband, Adam, a renowned surgeon. They’re attractive, wealthy, and in a house of open windows, so exposed.

After their mother passes, three estranged siblings reunite to sort out her estate. Beth, the oldest, never left home. She stayed with her mom, caring for her until the very end. Nicole, the middle child, has been kept at arm’s length due to her ongoing battle with a serious drug addiction. Michael, the youngest, lives out of state and hasn’t been back to their small Wisconsin town since their father ran out on them seven years before.