ACT I

The Beauregard mansion sat on a hill in the Tremé neighborhood of New Orleans like a tooth that refused to fall out. It had refused to fall out for a century and a half, standing through hurricanes, through the rise of jazz, through the decline of the aristocracy that had built it, through wars and floods and the slow, patient erosion of a city that was slowly sinking into the bayou.

Isabelle Beauregard inherited it on a Tuesday in March. She was thirty-four years old, unmarried, childless, and possessed of the particular brand of exhaustion that comes from spending your entire life being other people's disappointment. Her father had died that morning, and with him died the last illusion Isabelle had entertained that her family might one day be normal.

The mansion was everything she remembered and nothing she expected. She had visited as a child, in the brief periods when her father allowed it, and remembered it as a place of vast rooms and echoing corridors and a grandmother who spoke in riddles and measured time in generations rather than years. What she did not remember was the geometry.

The first thing Isabelle noticed upon entering was that the grand staircase was in the wrong place. She remembered it on the left side of the foyer. It was on the right. Not just the right side of the right side, but on a wall that, according to the blueprints she found in her father's study, should have been solid brick. She stood in the foyer and stared at the staircase and felt a slow coldness move through her stomach, the kind of coldness that had nothing to do with temperature and everything to do with the sudden, unshakable certainty that the world was not what it seemed.

ACT II

Isabelle spent the first week in the mansion walking its corridors, measuring rooms that should have been standard rectangles and finding that they were not. The library was twenty feet longer on the north wall than on the south. The master bedroom had a corner that was not quite ninety degrees, not quite one hundred eighty, but something in between, an angle that made the furniture fit wrong and the eyes track toward it compulsively, the way eyes track toward danger.

The second thing she noticed was the substance. It appeared first in the basement, seeping from the foundation walls like sweat from skin. It was black, viscous, and smelled faintly of ozone and old earth. Isabelle touched it once, drew her finger across the stone wall, and brought it to her nose. It smelled like the air before a thunderstorm, but older. Ancient.

She called a contractor, a man named Deshotels who had been fixing foundations in New Orleans for forty years and had seen everything except this. Deshotels looked at the black substance, ran a thumb across it, frowned, and said, I have never seen anything like that. It is not water damage. It is not mold. It is not anything I know.

He recommended she tear out the foundation and pour new concrete. Isabelle said she would think about it. She did not think about it. She thought about everything else.

The third thing she noticed was the corridors. She was walking from the library to the kitchen one evening, carrying a cup of tea that she would not drink, when she turned a corner and found herself at the entrance to the foyer. She had walked perhaps twenty feet, through a corridor that should have ended in a wall. Instead, the corridor curved, imperceptibly at first, then more obviously, bending back toward where she had started, until she was standing in the foyer looking at the staircase that was in the wrong place.

She walked it again. Corner to corner to corner. Twenty feet. And she was back where she had started. The corridor had looped. Not physically, not in any way that a tape measure could detect. But if you walked it with purpose, with the intention of going somewhere, it would bring you back to where you began.

Isabelle sat on the bottom step of the staircase and put her head in her hands. The house was alive. She knew this with the same certainty that she knew her own name, which was still Beauregard, which was still the name of a family that had once owned plantations and slaves and had built this house on both. The house was alive, and it was growing, and it was incorporating her into itself brick by brick, corridor by corridor, corner by impossible corner.

ACT III

Isabelle stopped inviting people over. She stopped answering calls from her mother, who called once a week to ask, in a voice that was all concern and none understanding, when Isabelle was going to do something with her life. She stopped going to church, not out of rebellion but out of a simple realization that the people in the church did not understand houses, and Isabelle was beginning to understand her house better than she understood anything else in her life.

She began to notice that the house responded to her presence. The black substance appeared more frequently when she was home, seeping from walls in patterns that almost looked deliberate. The corridors shifted subtly when she was not looking, rearranging themselves into configurations that made no geometric sense but felt, in some deep part of her, correct. The rooms grew larger when she entered them and smaller when she left, as though the house was breathing, expanding and contracting around her presence like a lung.

One night, she stood in the master bedroom and pressed her hand against the wall. The wall was warm. Not the warmth of a room that had been in the sun. The warmth of skin. Of living tissue. She pressed harder and felt, faintly, a vibration, like a heartbeat transmitted through stone and plaster and the memories of everyone who had ever stood in this room and breathed this air.

The house was incorporating her. She understood that now. It had started with the geometry, with the impossible angles and the looping corridors. It had continued with the black substance, which was not a substance at all but a secretion, something the house produced the way a body produces mucus or sweat or the cells that rebuild itself from the inside out. And it would end with her, with Isabelle Beauregard, fading into the walls and the floor and the staircase that was in the wrong place, becoming part of the house's living structure, her consciousness absorbed into the same vacuum fluctuations that held the building together.

She did not fear it. That was the most unsettling part. She was not afraid. She was curious. She was, in the way that Beauregards had always been curious, the way her grandmother had been curious when she measured time in generations, the way her father had been curious when he allowed her to visit this house that was slowly turning into something else, the way she was curious now, pressing her hand against warm walls and feeling the house breathe.

ACT IV

Isabelle Beauregard died six months after inheriting the mansion. The official cause was heart failure, though no one who examined her body could have said how a thirty-four-year-old woman's heart could simply stop without warning, without history, without reason. The funeral was small. Her mother attended, along with three cousins and a woman from the church who brought a casserole and a look of relief mixed with satisfaction, the look of a woman who had been waiting for Isabelle to be gone for a very long time and was glad that the waiting was over.

The mansion stood. The corridors still looped. The black substance still seeped from the walls, though newer owners would call it something else: mineral deposits, residue from the bayou, nothing to worry about. The staircase remained in the wrong place, and anyone who walked its corridors with purpose would find themselves returning, again and again, to the foyer, to the staircase, to the beginning of whatever journey had brought them there.

Isabelle was in the walls. She could feel the house breathing. She could feel the corridors shifting, the rooms expanding, the slow, patient incorporation of her consciousness into the living structure that had been growing long before she arrived and would continue growing long after she was gone.

She was not afraid. She was, finally, home.