She thought she’d gotten a handle on the house’s broad layout, but she still became lost while looking for her parents’ room. With the door closed, it blended in with all of the other sealed doors, and she ended up opening four wrong doors before she was finally greeted by the sight of her parents’ master bed and, above it, the strange, sickly stain in the ceiling.

Margot shut the door again, refusing to stare at the room’s contents—or the mirror—for even a second longer. Instead, she began moving through the halls around it, eyes trained on the ceiling as she looked for an entry hatch.

She found one just around the corner. It blended into the wood ceiling, almost invisible except for the half-moon fingerhold and a silver bolt lock.

A fresh wave of discomfort moved through Margot. She’d seen that kind of sliding lock on almost every apartment door in the city, but never on the underside of a ceiling.

Who had reason to lock their attic?

She shook her ladder open, propping it under the entry hatch, and climbed. The bolt was stiff and took effort to scrape free, but then Margot planted her hand on the wood hatch and shoved.

It was heavier than she’d expected and ground up in increments. Margot, muscles beginning to strain, took another step up and added her other hand to the hatch. It finally reached its tipping point and rocked over, crashing into the attic’s floor and leaving a two-foot-by-two-foot opening into the ceiling.

The stepladder wasn’t high enough for Margot to walk into the attic, but by standing on the highest step she was able to get her head and shoulders through. She pulled her phone from her pocket and switched it to flashlight mode.

With her other forearm resting on the floor to hold herself steady, Margot raised the phone and stretched it ahead.

It was clear that section of the attic was one of the older parts of the house. Deep fissures ran through the wooden beams. Repairs had been made—sometimes with metal brackets for support, sometimes by replacing whole sections of wood—but the area reeked of age.

She squinted, turning slowly, shining her light as far as it would go. Heavy crossbeams blocked much of her view. Dust motes rotated in the pale light. She craned her neck, her breath held, searching the layered shadows.

Don’t stray too far after dark.