Nina can never forgive Maggie for what she did. And she can never let her leave. They say every house has its secrets, and the house that Maggie and Nina have shared for so long is no different. Except that these secrets are not buried in the past. Every other night, Maggie and Nina have dinner together. When they are finished, Nina helps Maggie back to her room in the attic, and into the heavy chain that keeps her there.

Home alone with her young children during a blizzard, a mother tucks her son back into bed in the middle of the night. She hears a noise—old houses are always making some kind of noise. But this sound is disturbingly familiar: it’s the tread of footsteps, unusually heavy and slow, coming up the stairs. Shrouded in the shadows, she sees the figure of a man appear down the hallway. Terrified, she quietly wakes her children and hustles them into the oldest part of the house, a tiny, secret room concealed behind a wall.

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.

Kit Darling is a maid with a snooping problem. She’s the “invisible girl,” compelled to poke into her wealthy clients’ closely guarded lives. It’s a harmless hobby until Kit sees something she can’t unsee in the home of her brand-new clients: a secret so dark it could destroy the privileged couple expecting their first child. This makes Kit dangerous to the couple. In turn, it makes the couple—who might kill to keep their secret—dangerous to Kit.

Whitney had some misgivings when she dropped her increasingly moody teenage daughter, Amelia, off at Lauren’s house. She’d never met the parents, and usually she’d go in, but Amelia clearly wasn’t going to let something so humiliating happen, so instead Whitney waved to her daughter before pulling away from the little house with the roses in front. But when she goes back the next day, an elderly couple answers the door - Amelia and Lauren aren’t there, and this couple swears they never were, that she’s at the wrong house.