Sam is furious, ripping into a box marked “XMAS DECOR.” She’s not careful. The metal box clatters out, and she jumps back, staring at it—too new, not dusty enough. She kneels, her breathing loud in the dank basement, and fumbles with the latch. It opens. With a sharp intake of breath, Sam gasps, her hand hovering over the contents. She picks up a photo first: it’s of her, through her kitchen window, laughing on the phone, a memory she doesn't recall. Whispering, trembling, she asks, “When…?” She picks up a simple silver stud earring, touching her own bare earlobe, remembering she had looked for this. Then she sees the key, cold in her hand, and recognition is instant and visceral. To herself, in a horrified realization, she whispers, “The rock. The stupid fake rock.” She remembers buying it, a 'security' measure, and putting the spare key under it the day they moved in—a secret she never told Jack, a memory she’d forgotten until this moment. She closes her fist around the key, the metal biting into her palm, solid, terrifying proof. Her fear crystallizes into cold rage. Louder, to the empty house, she declares, “You were in here. You are in here.” At that exact moment, from upstairs, a distinct, metallic CLICK-CLUNK of the front door deadbolt turning echoes through the house. All rage drains from her face, replaced by pure, primal fear. She looks up at the basement stairs. A floorboard CREAKS directly above her head. Someone is standing in the hallway, right at the top of the stairs. Now there is only the sound of her stifled breath, and the slow, rhythmic SQUEAK of the lightbulb chain beginning to sway above her.