A lot of Kiwis end up moving to Australia. The weather’s better and the economy is stronger, so there are more jobs out here and the pay is better. I’m teaching building science at a rural university, and I don’t think I’ll come back. I missed the memorial service last month, and I can’t think of anything else that could get me to come home. No family or anything. Maybe I could get my old job back in Auckland, but I like this place much better. It’s dry here. Even when it rained last week, that was only the second or third time since I moved. When I walked around afterwards all the water had soaked into the ground. You couldn’t even tell. When I got home that afternoon I realized it had been a year exactly since I first saw Marler House.

We never met the owner. Apparently he rented the house out as soon as he inherited it, without ever stepping foot inside. That happens a lot. Someone from an agency showed us around the building, though obviously it was the first time he’d ever seen it too.

“Well, those are all the main rooms,” he said. “I’ll let you guys look around now if you’d like. Again, I’m sorry about the electricity.”

He was a young man, bald, without any eyebrows even. He wore a dress shirt and cufflinks but no tie. There were four of us there: Victor, Eva, Stephen, and me, and he had started out by addressing each of us in turn. But after a while he began to look only at Victor when he spoke.

“Something—a rat—chewed through a cable. The electrician won’t come in on the weekend, but we’ll fix it before you get back.”

“We’ll need electricity,” said Victor. “But the house looks good.”

Anthony Marler was a Scot, like most settlers in this part of the country; advised to leave Aberdeen for his lungs’ sake, Marler walked off an immigrant ship at Port Nicholson only to find that he’d exchanged one rainy island for another. Still, Marler made the best of it: a country lawyer, he built a “gothic” pile in the North Island, an imitation in wood and paint of the stone houses back home. The effect was not completely successful. “Looks like Miss Havisham’s wedding cake,” said Eva. “Covered in cobwebs.” None of the others were much interested in history. But I think we all knew Marler House would be perfect the moment we saw the river: cold black water, flowing too rapidly to stand up in and so close to the building you could see it from the windows. I could imagine a canoe slipping silently down it, ochred, carved, rowers likewise painted and likewise carved slicing the water at narrow angles with their oars. But I later learned that the river was only a canal cut in the nineteenth century to bring mountain water down across the high country. It had a number (Irrigation Channel Thirty-Eight), but no name in any language.

Behind me Victor was still talking to the agent, who was answering questions as beads of sweat welled up on his head. Victor was tall, bearded, and loud; without really meaning to do so, he could browbeat nervous people into a state of near-panic. “—for our work. A backup generator somewhere maybe. Is there room in the house? Nowhere else? Fine. We'll need to pull up this carpet too, everywhere except the main corridor. Is the floor hardwood underneath? Oh, good. Well, I’d better talk to Stephen, do some measurements. Paint samples too, maybe, I think we brought the kit. But I think we’ll take it. We’ve been looking for something like this for a while. Is it haunted?”

“I’m so glad,” said the agent. “It’s a lovely property for the summer.” Then he paused, finally taking in Victor’s last query. “Sorry?”

“Haunted?” asked Victor again. “The house. Native burial ground, women in white on the staircase? Cold patches in the corridor, rattling chains? Ectoplasm?” He said the final word slowly.

“No,” said the agent. He smiled, then stopped smiling, then smiled again more nervously. “Very funny, Mr. Egan.”

Victor clapped the man on the shoulder. “Kidding. Glad to know we’ll be starting from scratch.” The agent looked unhappy.

Our team’s theoretical approach was developed by researchers in Britain, but with innovations of our own. I think most of it is still covered by an N.D.A., but I can tell you we were the first to realize the significance of running water. That was one element shared by each “haunted” house that we had investigated. (Two others were single-glazed windows and foundations built on clay. Marler House had both.) The list of elements was one of the first papers the Building Science Research Unit published. My name, Mary McCrea, was first on the paper, although really it was all Victor’s work. Starting from a list of every reputed haunted house in the North Island, we excluded the obvious fakes and tourist traps then put the remainder through a battery of tests: mold, lead paint, that kind of thing. Once our carbon monoxide alarm went off as soon as we had stepped into the kitchen, and the four of us sat on the front step with the owner as fire trucks roared up the drive. Occasionally we proved a haunting was fake. It got us into the newspapers (every journalist thought he was the first to call us the “Ghostbusters”), but instead of being satisfied I was always horribly embarrassed. Victor loved it, though: one year a local skeptics’ club awarded us a “Hitchens Cup.” On the trophy my name was spelled wrong. It got to the point where my students started humming the Scooby Doo theme whenever I turned to the whiteboard.

Still, we always got research grants without any trouble—nobody could deny we did good work for not too much money—and less than a month after we’d first seen the house, the four of us began installing the equipment for Victor’s big experiment. It was November, early summer, and the garden smelled like hard earth before rain. The men were already inside the house. As I walked up the path, an upstairs window opened and some knotted, blood-colored thing spilled out, writhing and unspooling as it fell. A Turkish rug; for a moment it opened completely in mid-air and I could see the whole pattern. Then it hit the ground and crumpled in a heap. A spray of dust glittered in the sunlight. A moment or two later Victor peered out the same window. “Did I hit anyone? Oh, hello Mary. Come up here and give me a hand. I don’t want anything to absorb the sound in here.”

It took us less time than I expected to set everything up that day, although we did have to stop and fix some back-to-front wiring. Floor-standing speakers, an old-fashioned amplifier with glass tubes, a wide ring of subwoofers daisy-chained together: Most of the equipment was gear you could find at any used hi-fi shop. None of it cost much. There were a few specially made parts, manufactured to Eva Mendes’ specifications by overseas suppliers; she and Stephen were secretive, and I still don’t understand what most of the components were even for. I remember seeing Eva sticking suction cups to the panes of the riverward window, each tethered droopily to a black knot of cable on the ceiling. There was something disgusting about that clot of wire. It looked like a heart. Eva also put something in the bathtub upstairs, some piece of machinery, then ran the taps till the bath was full of water. “Keeps it cool,” she said. I never got a good look at it. After the first morning someone drew the shower curtain; in the draft (and there always was a draft) the yellow plastic filled and emptied like a lung. Pretty soon everyone started using the downstairs bathroom, though it was much smaller.

After we’d treated the house (inside doors open, outside door shut fast, mirrors turned to the wall, all acoustic muffles and baffles removed), Victor showed us the generator. “I rented it out in the town,” he said. “You heard the property agent: Electrician doesn’t come out weekends. Old wiring in this place.”

“I suppose you want us to help you move it,” said Stephen. It looked very heavy.

“Move it, you reckon? I quite liked it there, on the front step. Well, if you think we should move it, come lend a hand. All of you, actually. Where’s Eva? I want this thing in the basement, so it can power the whole house. Mary and Stephen, you take the front and walk backwards.”

The generator was so heavy the four of us could hardly raise it above our knees. With our first step, the weight shifted with a liquid noise. “Why,” said Eva, “did you fill it up before we moved it?”

The basement door was in the kitchen. Some quirk of air pressure in the house meant the door stuck fast until you gave it a mighty tug. Then it would slam back on its hinge and snap back closed. Stephen propped it open with a brick. “Is there a light?” he asked.

“Switch is at the bottom of the stairs,” said Victor. “Before I forget: you need a key to turn this thing off. Safety feature. Hold on to it, Mary?”

Eva frowned at me when I took it. “Can we get a move on? I want to have everything ready before dinner.” Sometimes I used to think she was envious of my relationship with Victor.

“Watch your footing on the stairs,” he said. “Lower than you think. We’ll lift on three.”

I don’t blame anyone for what happened. Perhaps Eva could have been a little more careful. Victor was very good. He set me up on the downstairs sofa and made me tea.

“Will you be okay? Can I get you a—you already have a tea—do you need anything else?”

“God, I feel so silly. I won’t even be able to help you pack up tomorrow.”

“What?”

“Pack the equipment up. For the experiment.”

“Mm,” said Victor.

Stephen was in the doorway. “Eva says the generator’s fine. How’s the ankle?”

I opened my mouth. “Mary’s all right,” said Victor. “Nasty sprain, though.” I flexed my foot a little and winced. “Better not put too much pressure on that ankle. Stephen, could you move her things down here? We’ll set her up in the living room.”

Stephen didn’t look like he was listening. He was chewing his lip.

“Get Eva to help you,” said Victor.

“I’m not so sure that is a sprain,” said Stephen. “Maybe we’d better call someone.”

“What, an ambulance? I think that’s a bit excessive. Don’t you think, Mary?”

I flexed my foot again; it didn’t hurt much this time. I heard the packet of frozen peas crinkle.

“Besides, if Mary went to the hospital we’d have to cancel everything. Be a shame.”

“Listen,” said Stephen, “maybe you should let—”

“It’s fine,” I said. “I really think it’s only a sprain. I want you to keep going.”

“There you go,” said Victor, and before he stood up he squeezed my hand. “Now, should we keep bothering her? Or should we let Mary have some rest? There’s still a lot to do.”

“Could I have a glass of water, please?” I said. But Victor was already walking toward the door. I don’t think he heard me.

I remember waking up, not falling asleep. A dark room, high ceilings. Somewhere, a clock ticking and loose paper rustling in the draft. This happened sometimes: the texture of dreams broke in on waking life. I couldn’t move or cry out. Frigid river water; musket balls buried in the bank, shallow enough to pick out with finger and thumb. That brought back another memory, or dream, and I closed my eyes. Finger bones in the mud. Water contaminated with the odor of death. Something heavy on my chest pinned me to the sofa and I dreaded now to open my eyes. It took me a long time to realize the others must have turned on the machine upstairs.

I don’t know what Victor originally specialized in; his degree was in physics, and I didn’t understand most of what he told me about it. But he had the brittle energy of an autodidact, and most of his research was in a field he invented himself: the architectural basis of supernatural experiences, or why some buildings are “haunted” (air quotes, always) and some aren’t. I still have the scoring sheet somewhere: twenty-three yes/no questions and we could guess, with a fair success rate, whether or not a house was meant to have a ghost. It was Stephen Wong who made the breakthrough: What we call “hauntings,” in almost every case, are actually the effects of sound too low or high-pitched for human perception. The liquid in your eyes and inner ears ripples; the hairs on your arm stand up; we think something happens in the spinal cord, too, but we never had the chance to use an M.R.I. Some people are affected more than others, but everyone responds to it at least a little. I’m unusually sensitive to the effects. Victor noticed that right away.

Once we worked that out, it wasn’t long until Victor wanted proof: if we could create our own “haunting” in any house we chose, we could do away with superstition entirely. Or so the theory went. So we picked Marler House, verifiably unhaunted and fitting all our requirements, and installed all the equipment we’d need to conjure up ghosts of our own. Without ever discussing it outright, we all agreed to be the first test subjects.

Half an hour after I woke up, Victor and the others came downstairs. Stephen turned on the light.

“Sorry, Mary, didn’t mean to leave you in the dark,” said Victor. “How about that, eh? Could you feel anything from down here?”

Eve had walked right up to my sofa; before I could speak she’d unsuckered something from my forearm. “Yes,” she said, reading something off a screen. “Just look at this. Heart rate through the roof from the minute we turned it on. More than any of us, even though she was farther away.”

“What’s that?” I said. Eva was showing the screen to Victor, who nodded.

“Good,” he said, “write that down.”

“What is that?”

Victor looked up. “We all agreed to wear one,” he said. “Didn’t want to wake you up when we were putting them on.”

“The first test went quite well, Mary,” said Stephen. I wished they’d stop using my name. “If there’s anything you can add?”

I closed my eyes and tried to remember. “I don’t know. The river.”

“Funny,” said Stephen. “We were thinking about it too. Upstairs.”

“Nothing funny about it,” said Victor. “River’s the only point of interest for miles, most of this place is farmland. Our imagination focuses on whatever it can.” Eva was writing something down. When she saw me looking she moved her notebook so I couldn’t see.

“Anything else?” asked Stephen gently.

“No. I’m sorry. Just bad dreams.”

The next morning the others went into the village, half an hour away on gravel roads. I listened to the scrape and crackle as the van left. Stephen asked if I needed anything; I told him I had my Kindle, I was happy. They were back much sooner than I expected.

“Whole bloody place is closed for the long weekend,” said Victor. “It’s like they don’t want to make any money. Could have a lot of tourists, place like this, nice old buildings. But no. Got you this pastry from the supermarket.”

“Thank you,” I said. “What is this?”

“I don’t know,” said Victor. “Peanut something.”

“If it’s peanuts I can’t eat it.”

“Oh. Sorry. You should have said something.”

“I’ll eat it,” said Eva.

The next test was that afternoon. Everything was in place; it didn’t take long to set everything up. I wanted to help, so Stephen gave me some soldering to do. When I hobbled to the bathroom, putting my weight on Victor’s shoulder, I think I saw Eva re-doing it all in the kitchen. The equipment was ready well before dark, and we decided to do a daylight test, to see if that would make any difference. This time Victor stayed downstairs with me. He sat in a chair next to me, bouncing his leg up and down, sometimes standing up and wandering around the room.

“I’m sorry about your ankle,” he said. “I hope —”

Then Victor froze, and flexed his jaw. A second later he relaxed. “I was wondering if I’d notice them turn it on. Didn’t feel much last time.” I didn’t say anything. “For a moment I could have sworn old Tony Marler was right here with us. How do you feel?” Victor went right on without a pause. He was starting to sweat. “I wonder if Eva and Stephen have turned up the juice a bit this time. Wouldn’t be surprised. Say something, Mary, I feel like I’m talking to myself.” Victor laughed, and then quickly stopped. I suppose he didn’t mean for it to sound like that.

“Why did you say, Tony?”

“What?”

“You said Tony Marler. I didn’t realize you knew his first name.”

“Eh? Oh. Must have heard you say it. Seen it written down somewhere. Oh, that’s better.”

A sudden slackness, like a tense muscle released; the sudden awareness of sweaty clothes cold on my back; they’d turned the machine off upstairs.

“I need some fresh air,” said Victor. He looked out the front windows, towards the river. “There’ll be more sun out the back, actually.”

Nobody said much over dinner. Every takeaway place was closed except a shop in the village that sold fish and chips. They were cold by the time Stephen brought them back. The machine had broken, not forever, but beyond immediate repair. Something went wrong with the power supply—the cable had worn away or been chewed through or something—and the generator didn’t start up.

“Must have broken in the fall after all,” said Eva, glancing at me.

“Let’s get some sleep,” said Victor. “Someone else finish my chips, I’m not hungry. We’ll start packing up tomorrow morning.” He must have seen the look on Stephen’s face, because Victor leaned over and squeezed the other man’s shoulder. “I’d have liked to run another test, too, but I think we have enough to publish. Best thing to do is make this one an early night. Chalk it up to experience.”

Horrible dreams that night. The river again; something moving under the mud, in the dross. The livid color of a cave-thing, blindly struggling to the surface. The feeling of wet, hairless skin touching night air for the first time and turning to the source of that awful sound: the old house. I opened my eyes. The moon, half-empty and low in the sky, shot pallid light into the room. The generator was running. I could hear it coughing and groaning somewhere below me. The machine was on. Something was in the house. Something from the river. I knew it beyond doubt, and as I lay rigid I heard the front door scream on its hinges, swinging in the wind.

Sitting up made me feel sick. The stool next to me didn’t support my weight: It shot from under my hand when I leant on it. The empty water glass skidded on the floor and broke, each sharp edge catching moonlight. I think I cut my head in the fall. Shallow, but it bled: The hospital staff took the wound as a chance to discount the rest of my story.

I made my way slowly, dragging my weight by the elbows and feeling my way ahead of me, so gently that once I ran my fingers across the broken edge of my glass without a cut. With my face so low, I could feel every breeze that stirred the house. In with the rest there was a cooler current of night air. It carried the fetid stink of black mud that had never seen sun. Eventually, I felt something velvet: the hem of the curtains. Perhaps they would hold my weight. Breath held, I pulled hard with both arms. One ring popped, then another, louder. I saw the bent fleck of metal fly into the room. Then I was up, breathing shakily.

I lurched and staggered towards the hall, dividing my weight between one foot and the wainscot. Someone had shut the inside doors, and with sweat pooled in my palms it took two tries to turn the handle. So much of my weight rested on the knob that I nearly fell again when the door swung suddenly into the corridor. From the hall I saw the moonlight coming in from the juddering front door as it opened and closed, slicing the light into wedges and shafts that shot across the hall. I wanted to get to the kitchen. Normally it would have taken only a moment to reach it, but I moved in darts and lurches, timing it so I stood still when the hall was dark. I flinched when I trod on the carpet: It was soaked through, and with each step stinking river-water oozed up around my feet. Behind me were the stairs to the upper story, where I could hear the machine buzz and whine. There was no sign then of my companions; there has been no sign since.

At last I made it to the kitchen. I leant my full weight on the countertop and took a deep breath, my first since I had fallen into the corridor. Then I froze. Some sound was coming from behind and above me: on the stair. I heard it again after a moment, then a third time. First, there would be a heavy creak. Then a soft scratching, gentle and even, louder and softer in a steady cadence. Then the creak again, lower, as the thing moved down a step. The kitchen was dark, but I knew roughly where the basement doors were, and anything was better than standing still. I pushed myself off the kitchen counter with both hands, and the momentum carried me across the empty expanse of floor. As I moved I felt something click and grind in my ankle and the pain made me cry out. I stifled the noise in a moment, but too late: the sound on the stair stopped for a moment and then began again, much faster. Soft scratching, up and down, the sound of long sharp fingers blindly feeling the steps, reaching into each crevice and each corner with every tread and missing nothing.

The basement doors snapped open and closed with a terrible sound, leaving me on stone steps in darkness. Each was steep and sharp-edged. The only way down was to crawl. Tread by tread, riser by riser I went, walking with my hands. Once I missed a step and slipped forwards, skinning both arms from wrist to elbow. I heard, or thought I heard, something from the kitchen then: it was close behind me. Before I reached the last step the basement doors snapped open and closed, and a gust of foul air disturbed the must and mold of the basement.

Faster and faster I crawled, and when I reached the floor I wasted no time rising to my feet but kept moving on my hands and knees towards the generator. The din was enormous. With both hands I looked for an off-switch on the groaning, clattering thing. Instead I found a keyhole. The key to turn it off. Of course. The safety feature. Where was it? Victor had given it to me. With growing panic I checked one pocket after another. The key was missing. I couldn’t turn the generator off.

Now the smell was almost unbearable. I could hear nothing over the generator. What were my options? I couldn’t make it back up those steps. I couldn’t hide in an empty room. The only choice left to me was whether to remain on the ground or upright. I wanted to stand. So I backed toward the wall, and slowly rose to my feet. When I tried to settle my weight on my ankle it folded again, and to keep my balance I grabbed the first thing I could feel. It was the light switch.

They found me a few days after the long weekend, lying in the basement with the lights on, the generator still running. I am told that I was severely dehydrated. For some reason the first people in the house were firemen. The police weren’t far behind: a young Māori woman in civilian clothes came to interview me in my hospital bed. I only realized I was suspected of a crime after the second visit. My lawyer said not to worry. With my ankle in that state they couldn’t build any reasonable case. I stopped following the case after I left the country. Eventually I think they switched to questioning some local vagrant. I hope he gets off.

I’m pretty good on my crutches now. I can go for a whole twenty or thirty minutes at a time. It is good to feel the sun on my face. Another thing I like better here: the sun rises early and goes down late. You can get up before anyone else, and see the whole campus pinned under flat, bright light without any shadow. This morning as I went along my usual route and smelled the dry dusty air, I tried not to think about what I saw, caught in the light, in the basement of Marler House.