One Scriiiiiiiitch. I wake with a start, unnerved by the sound zipping across the dark room. It echoes off the walls and snakes back to me in multiple waves. I lie in bed, completely still, eyes wide open, until the noise fades. Not that it was ever there to begin with. Decades of experience have taught me that it was just in my head. Dream, memory, and hallucination all at once. My first since coming back to this house.

Honestly, I''m surprised it took so long, especially with the anniversary of what happened here fast approaching. Sitting up, I look to the clock on the nightstand, hoping it reads closer to dawn than midnight. No such luck. It''s only quarter after two. I''ve got a long night of no sleep ahead of me. With a sigh, I reach for the notebook and pen I keep next to the clock. After much squinting in the darkness, I find a fresh page and scribble four frustrating words. Had The Dream again.

I toss the notebook back onto the nightstand, followed by the pen. It lands with a clack against the notebook''s cover before rolling onto the carpet. I tell myself to leave the pen there until morning. That nothing will happen to it overnight. But the bad thoughts arrive quickly. What if the pen leaks, its midnight-black ink staining the cream-colored carpet? What if I''m attacked in the middle of the night and the only thing I can use to defend myself is an uncapped Bic, which now sits out of reach? That second one, as alarming as it is improbable, pulls me out of bed. I grab the pen and set it on the notebook. There.

Much better. Anxiety soothed-for now-I''m about to crawl back under the covers when something outside catches my attention. A light. Not unusual for Hemlock Circle. Despite the lack of streetlights, it''s never completely dark here. Light spills through bay windows onto immaculate front lawns and brightens second-floor bedrooms before the sun rises and long after it sets. The sconces flanking the Chens'' front door burn from dusk to dawn, warding off both trespassers and the bats that occasionally try to roost in the eaves. All summer long, the Wallaces'' backyard pool glows an alien blue.

At Christmas, lights twinkle at five of the six homes in the neighborhood, including the Patels'', who put theirs up at Diwali and don''t take them down until a new year begins. Then there are the garage lights. Every house has them. A pair of motion-activated security lights centered above the garage doors that glare like headlights when triggered. In the evenings, they flick on and off around the cul-de-sac with the frequency of fireflies as residents return from work in the waning light, go out to fetch the mail, haul recycling bins to the curb. As it gets closer to midnight, a few will continue to spring to life. When deer skulk through the neighborhood on their way to the woods. Or when Fritz Van de Veer sneaks out for a cigarette after his wife, Alice, has gone to bed.

The light that''s caught my attention is the one above the Patels'' garage, two houses away. It illuminates a patch of their driveway, the glow turning the asphalt ice white. Curious, I go to one of the windows in a bedroom I still don''t consider my own. Not technically. The room that once was mine , and in my mind still is, sits across the hall, now vacant. This is my parents'' bedroom, where I rarely ventured as a child. Now, though, through a series of recent developments I''m still grappling with, it''s become my own. The windows in this new room offer a panorama of Hemlock Circle.

From where I stand, I can see at least a piece of every house on the cul-de-sac. I glimpse a sliver of the old Barringer place on the left and a corner of the Chens'' house to the right. Across from me, in full view from left to right, are the Van de Veers'', the Wallaces'', and the Patels'', where the garage light still glows. What I don''t see is anything that could have set it off. Mitesh and Deepika Patel are presumably inside and fast asleep. No animals scurry from the light. No wind blows that could have caused a nearby branch to sway hard enough to trigger the motion sensor. All I can see is an empty driveway on a quiet cul-de-sac in the dead of night.

Soon I can''t even see that, for the Patels'' garage light suddenly goes out. Ten seconds later, the one at the Wallaces'' house clicks on. It''s next door to the Patels'', separated by the single road that leads into the cul-de-sac, which is currently free of cars, free of people, free of anything. I draw close to the window, my nose almost touching the glass, straining to see something-any small thing-that could have triggered the light above the Wallaces'' garage. There''s nothing. Nothing visible, that is. Still, I stay pressed to the window, watching, even after the Wallaces'' garage light clicks off. The only thing I can think of that could have triggered it is a bat.

They thrive here, as the Chens'' porch lights can attest, feeding off the many insects that live in the woods circling the cul-de-sac. They''re also notoriously difficult to see in the darkness. But then the light above the Van de Veers'' garage springs to life, and I know my theory is wrong. Bats flit willy-nilly, chasing prey. They don''t methodically move from house to house. No, this is different. This is . worrisome.

Unease spreads through my chest as I think about thirty years ago. I can''t help it. Not after what happened here. When the Van de Veers'' light turns off, I begin to count. Five seconds. Then ten. Then a full minute. Long enough for me to think that whatever is out there has moved on, likely into the woods, which means it was an animal.

Something simply too small and quick for me to spot, but not small and quick enough to evade the hair-trigger garage lights of the houses on Hemlock Circle. The tightness in my chest eases, and I allow myself a sigh of relief. Then the light above the Barringers'' garage turns on. The light itself is just out of view, but the glow it throws onto the lawn and sidewalk makes my pulse do a stutter step. Whatever''s out there isn''t gone. In fact, it''s getting closer. Several scenarios pop into my head, starting with the worst, because that''s my default mode. Always going straight to the most alarming, the most dire.

In this case, that would be that someone is circling the cul-de-sac. Someone I can''t see but who is definitely out there. Moving from house to house, searching for another child to snatch. Second in line, and just a shade less worrisome, is the idea that whoever is outside has come to case Hemlock Circle, testing the security lights to see how easy it would be to break into one of the houses here. The third scenario is that it''s just someone going for a late-night walk. Someone from one of the other cul-de-sacs located in this two square miles of suburban sprawl. Someone who, like me, is riddled with insomnia and decided to try to walk it off. But if this is just an innocent stroll, why doesn''t whoever is out there make themselves visible? The paranoid-but-logical answer is that it''s not an innocent stroll.

It''s something else. Something worse. And I, as likely the only person on Hemlock Circle currently awake, owe it to everyone else to try to put a stop to it. When the light at the Barringer house next door flicks off, I make my move. Knowing that this house is next, I hope to catch whoever it is in the act. Or at least make it known that not everyone on the cul-de-sac is asleep. I leave my parents'' bedroom and hurry down the hall to the stairs. On the first floor, my bare feet slap against hardwood as I cross the foyer to the front door.

I unlock it, fling it open, step into the warm mid-July night. There''s no one else out here. I can tell that instantly. It''s just me, breathing heavily, dressed in only a pair of boxer shorts and an LCD Soundsystem concert tee. I hear and see nothing as I cross in front of the house toward the driveway. When I round the corner, my movement triggers the security light above the garage doors, which flicks on with a faint click. For a second, I think someone else has set it off and whirl around, panicked. By the time I realize it''s just me, bugs have already started to swarm the garage light.

I watch their incandescent spinning, feeling simultaneously foolish and on high alert. An annoyed voice in my head that''s plagued my thoughts for years now, suddenly pipes up. Get a grip, Ethan. There''s no one out here. Just to be certain, I stand completely still, scanning the cul-de-sac for signs of someone else. I remain there so long that the garage light eventually switches off, plunging the driveway-and me-back into darkness. That''s when I sense it. A presence, faint in the night air.

It lingers in that way certain smells do. Cigar smoke. Perfume. Burnt toast. It''s like someone had been here mere seconds ago. Perhaps they''re still here, hidden among the trees that ring Hemlock Circle, watching me. You''re being paranoid, the voice in my head tells me. But I''m not.

I can feel it. The same way you can tell someone is in the next room, even though they''re not making a sound. What''s more unnerving is how familiar the presence seems. I don''t know why. It''s not like I know who''s out here-if it''s anyone at all. Yet the hair.