When we were young, my brother and I would play in the forest behind our parents’ house. Our father had given us antique walkie-talkies, inherited from his own grandfather. We loved to pretend we were an elite team sneaking through a woods filled with monsters. Dusk was the only time we played this game—never at night when it would be too frightening and never during the day when we wouldn’t feel afraid. It was a game about edges: almost too afraid to play, almost too dark to see, almost able to convince ourselves that the monsters were real or weren’t.

The crackle of the walkie-talkies and our voices pitching through the half light of the trees returned to me often when I was older, in dreams usually. We’d had a code for monsters then: “The stars are out.” A message to let each other know that we’d gone past our edge and it was time to find one another and go inside.

I would ask, as I crept through brambly berry bushes, pine needles pressing into my knees, “Are you there, Bravo? It’s me, Alpha. Are you there?”

And then, always, my brother’s voice, filled with static, would cut through the near night. “I’m here, Alpha, I’m here.”

“The shallower the roots of a tree,” I said, “the more susceptible it is to drought. However, there are ways to combat this: breeding trees to have roots that grow deeper and faster or with thicker xylem. Drought is no longer an unexpected catastrophe. In point of fact, it’s more expected than having a mix of rainfall and dry periods.”

The woman I spoke to, Catherine Evers, was the head of a funding program, and she talked to dozens of scientists a day—all of them with eyes going full street urchin in the hopes that she’d give them just a little more leeway to pursue whatever noble goal they had in mind. I didn’t like that tactic, though. It was better to just state the facts.

“And what exactly does your project do to benefit the trees, Ms. Monroe?” she asked.

Not “Dr.” but “Ms.” Noted.

“We’re working toward creating a product that would act as a sort of steroid for xylem, essentially—making it stronger and more efficient.”

“Shouldn’t we be focusing on fixing the drought, not the trees?”

“Seeing the forest, ma’am, isn’t always the best solution,” I responded. I knew already that she wouldn’t be funding us. “I work with trees, not weather systems.”

“Ms. Monroe, I’m in the solutions business. Meaning I provide solutions for research teams through funding, but also that I like to see that the place I’m funding is solution-oriented.” I stopped listening and began to nod at points where I expected she wanted me to.

My brother had always been better at this sort of thing: handsome and charming, quick to laugh at jokes even when they weren’t funny. I imagined that funders would leap at the chance to give him money. Working for the Institute, though, he probably never had to stretch those skills. Funding was as guaranteed there as a plant photosynthesizing.

Back at the lab, Karin saw my expression and sighed. “Another one bites the dust?”

Shrugging, I said, “Yep. Why can’t you do these meetings?”

“You explain things better?” she replied.

This was probably true. Karin was the kind of scientist who had trouble un-sciencing her language. “Maybe Alec could go next time?”

“He’d just end up yelling at everyone and you know it. You’re our only hope, Chetna.”

“Well, then, we’re doomed,” I said as I walked into the tree room. We had two rows of dirt beds filled with tiny saplings. I believed in the trees. I longed to see them survive. As the world got harder for them, I could feel it inside me, aching. It was hard to think of how tall a tree could grow when all you were looking at was its beginnings.

“How tall do you think it is, sis?” Akhil asked. He pointed to the tallest tree in the forest.

We were eleven, the age of showing off, and so I said, “Dunno, but I can find out.”

“How?”

“Climbing it,” I said.

“You’d never,” he said. He expected me to use math, logic, something to do with measuring distance and shadows probably.

I ran home and got the measuring tape. The climb itself was easy, as I had always been athletic. Halfway up or so, I looked out over the trees. Everything looked full of life, squirrels scurrying and wind rustling the leaves and birds chirping out warnings to one another—a stranger in their midst. Akhil looked so far away and small and young, younger than me. I couldn’t see his worry, so I imagined that he was in awe.

I waved to him and that’s when I fell.

I don’t remember falling, just the rush of the air in my ears, then Akhil kneeling beside me. My father picking me up to carry me to the car, to the hospital. And Akhil holding my hand. He said, “It was my fault, Dad.” I never knew why he said that. His hand was warm. It reminded me that I was alive and everything was all right.

The morning after the funding meeting, I got the call. I spent most mornings running, getting up before the sun and taking off on a long jog. Long stretches of daily exercise were something my body had become so accustomed to that it was now more necessity than choice. Basketball had gotten me a scholarship in college. I enjoyed the movement of the game: the leaps and twists, the way everything could change suddenly. Basketball was rarely over until it was over. Life, in a way, was like that: the sudden twisting of the expected outcome into something else.

After college, though, I’d needed to find some kind of exercise to do on my own. To keep my mind clear. It’s what I had found in exertion: a moment of clarity when I was at my physical breaking point. Running made sense. I ran for an hour every day, sometimes two—especially on weekends. Sometimes I missed the camaraderie of a team sport, but I didn’t like being held to someone else’s time frame. In running, one only had to count on one’s own body.

I had three set running paths. My favorite went through the woods behind my apartment complex. In the mornings, there were rarely other people on it. I only chose it when I felt I needed it. Like a special treat, the doctor’s lollipop after the shot.

The sun was beginning to rise and light shot through the trees, casting shadows around me. In my pocket, there was a buzz. For a second, I wondered if it was a phantom.

Few of the calls one gets at dawn are good. Slowing my pace, I plucked the phone out of my pocket. Without checking who was calling, I pressed Answer. “Hello?”

“Chetna Monroe?” An unfamiliar male voice, slightly mispronouncing my name, putting too much emphasis on the “e.”

“This is. Yeah.”

“This is Ross Spenceler. Of the Trow Institute.” He took a long pause, letting that sink in. “There’s been an issue with the research station. It’s about Akhil.”

“What happened?” I stopped running, felt my body adjust to the loss of forward momentum—a feeling in the pit of my stomach like the drop of the elevator, the dip of the car over a hill, the Ferris wheel swinging down.

Akhil had been the first at everything. The first to walk. The first to say a word: “Amma.” The first to learn how to ride a bike. I was the watcher, first taking things in and only after consideration actually doing them. Where Akhil fell often, my steps were firm ones. Our mother said we should have been named “Steady” and “Ready.” We didn’t look alike, not really. Akhil took after our mother: rounder face, more delicate features. I looked like our father: sharp and angular. An aunt had once muttered that it was a pity our genders weren’t reversed. “It’s okay to be a pretty man. Akhil will be all right. But a strong-looking woman? Tsk. Poor Chetna.”

Akhil had responded to this overheard sentiment by placing a spider in the aunt’s teacup. The shrieking was delightful. Sometimes, one or the other of us would remember the incident and let out one of her shrieks: high-pitched and wailing. We’d both fall down laughing. It became a patented way for us to end fights. A promise, through laughter, that we’d always look out for one another.

But then.

The accident had been sudden. A bridge giving out. Hundreds of people died. Our parents had been driving home after visiting me. I always think of that part first.

“Get groceries more often, Chetna. Your eggs are three months out of date!” My mother’s voice, scandalized. That is what I remembered of the visit most, later when I was notified. I went to the grocery store after the call, filling the cart with things I’d never eat.

I put the groceries away, hands shaking, and tried to imagine my way back. Maybe time travel could exist, if I just tried hard enough. Then I could change it.

Akhil missed the funeral. He couldn’t leave, he said. The Institute was going through something. Akhil hated funerals: as a child, he would hide in the confessional booth during them. I’d yelled at him, called him a coward. At the burial, I filled both of my hands with dirt to place on the caskets, trying to trick our parents into thinking Akhil was there as well.

We hadn’t spoken since. It had been almost two years.

Sometimes, when I wanted to call Akhil, I’d instead look up the accident. In the years since, people had begun to speculate that it might not have been an accident at all. That it might have been the Shadows—an act of war unlike anything else we’d seen from them. There was no proof, save for uncorroborated reports of people seeing Shadows at the site afterward, lingering at the banks of the river and staring into the water. I had looked for them in photos of the aftermath, tried to see if I could spot one among the human faces. But in photos at night, it was too hard. Anyone could be anything.

At home, I packed quickly, though I wasn’t quite sure what to prepare for. My flight would leave in a couple of hours. The Institute had booked me on the first one that was available.

I hopped in the shower, washing off the sweat from the run. The hot water hitting my face made me feel more and more awake. The awakeness brought questions: Why had the Institute told me so little? The phone call had been clipped, mostly just information on what plane to take and how soon I should leave. I should have known their protocol well, but maybe it shook me more because I’d never been on the receiving side of news from them.

My father always said that the Institute prized their ability to say things without revealing anything of value. Doublespeak to the nth degree, he called it. I remember watching a program about Shadows with him, and a researcher from the Institute was being interviewed. She talked in negatives.

“We don’t know where Shadows came from, only that they came from somewhere. We aren’t sure where they first appeared or when.”

It was only when her segment was done that my father turned to me and said, “What did she tell you about Shadows?”

And I realized I only knew what they weren’t. You can paint a beautiful picture using negative space, but you can’t use it to understand something. Not really.

My arms had turned red. How long had I been standing in the shower? I turned off the water, standing for a moment in the quickly dissipating steam, and watched water dripping down the sides of the wall. What had my brother gotten himself into?

I took a taxi to the airport. When I landed, a driver would take me to the research base. A long drive, I assumed, as the base was located fairly deep in the forest. I’d seen pictures, but I’d never been there. All those trees. All that darkness hidden behind the trees.

“Shadows?” I asked my mother once. I was maybe ten or eleven. Old enough to have heard stories about Shadows, old enough to be scared of them. Our parents had both worked at the Institute. Had met there, actually. Our father had thought our mother was a secretary at first. Our mother was not a woman who enjoyed assumptions.

“It’s something we’ve known about for years. They’re not shadows like you’re thinking, Chetna.” Amma held her hands in front of the bedside lamp, making a shadowy rabbit on the far wall. “Not like this kind.”

“Then what kind?” I asked.

She sighed. “It’s hard to explain. They’re shadows that are existing where they shouldn’t. Shadows that don’t belong in our world.” She shrugged, reaching out to tuck a piece of my hair back. “We’re trying to study them.”

Always that word with the Shadows: trying.

Looking out the plane window, I could see the forest in the distance below. As a child, I might have thought that the forest went on forever. Where was the base amid all of the darkness and green?

The airport was mostly empty. It was more a place that people left from rather than came to. A tall man, around my age or a little younger, held up a placard with “Chetna” scrawled on it. If I hadn’t been expecting to see my name, I might not have been able to read the sign.

I nodded at him. “I’m Chetna Monroe.”

He held out a hand for me to shake. “Liam Green. Are you set? We’ve got a long bit of a drive ahead of us.”

I shook his hand, nodding. “Yeah. How long?”

“About six and a half hours.” He’d already turned and begun to walk away, so didn’t notice the look of shock on my face.

“Six and a half hours?”

“Yeah, it’s a jog into the forest. It’s a no-fly zone, so we can’t just helicopter you closer. Have you not ever been?”

“No, I haven’t.” I paused, unsure how much of myself to tell. “I’ve worked for the Institute, but only in an occasional and freelance capacity.”

Akhil had always been more interested in the Institute. We’d both, perhaps inevitably, gone into scientific fields: his was astrophysics, and mine was botany. Akhil thought about the stars, about the future. I did as well. There was no future without plants.

He’d called me the day he found out.

“I got a job at Trow!” His voice made it sound like he was actually jumping up and down as he spoke.

“Oh my goodness, that’s brilliant, Akhil!” Happy because he was so happy.

Liam and I walked briskly. I could easily match his pace. He led us into the airport parking lot and pointed out a Range Rover. “You’re Akhil’s sister, is it?”

“Yes.”

He took my bag and tossed into the Rover’s back seat. We got into the car. He was silent for a long moment, not starting the engine, just thinking. “I’m sorry,” he said.

“He’s just missing,” I said.

I’d seen a Shadow once. Dad had showed it to me, though he was probably not allowed to, when I visited the office he worked at. The Institute had offices around the world, small sets of researchers working on specific problems. Amma said it was like a web, the research radiating out from Trow. A Shadow had been caught in some sort of trap that looked like a mirror. A “shadow box” was what they were informally called, I found out later.

At first, I couldn’t tell that there was anything there at all: just my reflection.

“No, Chetna. Look at your reflection. Look closely.”

I peered into the mirror, at my own face staring back, and then noticed that my reflection’s eyes had silver pupils. I gasped and my reflection smiled.

“Dad, how can it look like me?” I was outraged. It was like it had stolen something from me.

“It’s what they do when you catch one. People in my department say they just copy to blend in, like chameleons. But I think they do it because they like to disconcert us.”

I looked away from the Shadow. I didn’t like it. The way I knew it was watching me. “Dad, what do they want? Why are they here?”

“We really just don’t know.” He peered at the Shadow, thinking about something. The look on his face was an unfamiliar one to me: somewhere between sadness and, possibly, fear.

Years later, I’d wish, over and over again, that I had asked him more. Not just about the Shadows. About everything: his childhood, his memories, the dreams he had at night. I wanted to have enough stories of my parents that I could understand them completely, could tell myself some piece of them every night so that I might never forget them. I think they were happy people. They loved us. That was a lot to have known, but still I wanted more. Don’t we always?

We didn’t talk. The road into the forest was barely a road at all: unpaved and only wide enough for one vehicle at a time. Finally, I broke the silence to ask a question that was gnawing at me. “What do you do if there are cars going in both directions?”

Liam smirked. “Hope the other one runs off the road.”

“Really?”

Liam laughed. “No. Of course not. The road is almost only used by people from the base. We know where everyone’s going, usually. We can avoid collision. I suppose if there ever was a situation, the person with the more off-road vehicle would go off the path.”

“What’s the base like?” I looked out at the forest. The trees were so dense that it seemed dark, almost as dark as night, though I knew—the way one can know something in a logical way even if one’s mind is screaming about how wrong it is—that the sun should be up for a few more hours.

He took a moment before answering. “I think it’s an interesting place. I work mostly in documentation. I’m a photographer, so maybe I don’t see as much as some of the science-minded. But it’s quiet.”

“Do you….do you work with the Shadows much?” I asked.

Liam took his eyes off the road for a second to look at me. “The shadows? I’m not sure what you mean.”

“Aren’t they mapping the Shadows? Isn’t that what they do there?” I wondered if Liam was messing with me again.

“Uh, is that a code name for one of the projects or something? I was told the base mostly did ecosystem research.” His voice sounded honest, if confused.

“Yeah, sorry. I’m so used to speaking in the terms of the Institute. Ecosystem work, yeah.” What exactly was going on? I wished my parents could tell me. They had always known the best way to explain things. I studied Liam as he kept his eyes on the road. Did people who didn’t grow up thinking about the Shadows become oblivious to them? Years and years ago, they were considered a huge threat to everyone, but now Liam didn’t even make the connection. I opened my mouth to ask more, then stopped. Maybe he was keeping secrets, and maybe I should keep my own.

The base sank back into its surroundings, giving it less of a camouflaged look and more of a defeated one. It was as if it had struggled to stand out but failed. I wondered if the design was on purpose.

“Base, sweet base,” Liam said.

“It’s less…impressive than I expected?” I said, hoping that by making my words sound questioning they wouldn’t cause any sort of offense.

Liam shrugged. “I kind of like that. We’re kind of, I don’t know, of the forest? Instead of in the forest?”

I nodded, glancing around at the trees that surrounded us, dense enough for anything to be hiding within their embrace. These trees were different from the ones I’d come to love on my daily runs. Not only their height, but also their stillness. These were trees that never bowed with the wind. I made a note to explore them later, after I knew where Akhil was.

Liam continued, maybe sensing that I didn’t completely agree with him or at least didn’t understand quite what he meant. “You know architecture at all?”

“A little. The famous stuff, sure.”

“The base reminds me of that Frank Lloyd Wright house, Fallingwater. It always looked like it was supposed to be there, just another rock jutting out.” He shrugged. “Maybe I just got used to the base and I’m making shit up in my head.”

I smiled at that. It was the kind of self-doubt of my own analysis that I sometimes felt but would never dare speak. “No, I get it. That makes sense.”

I followed Liam into the base. I’d asked to speak to Spenceler before doing anything else. Few people were in the open, so I had no idea how many were currently stationed there. We went through hallway after hallway, all of them seeming to loop back onto each other until I couldn’t remember which way would lead me out. Was that intentional design?

Finally, we stopped at a door.

Liam pressed the intercom. “I have Dr. Monroe, sir,” he said.

The door made a clicking sound as it unlocked. Inside, a man in a suit sat behind a large desk. He looked in his forties, with silver hair and black-rimmed glasses. It looked like he had chosen his look from the Distinguished Doctors catalog.

He stood up, extending a hand for me to shake. “Ms. Monroe, pleasure to meet you. We spoke on the phone. I’m Ross Spenceler.”

Taking his hand, I nodded once. I’d looked him up after the phone call and discovered that he was in charge of this particular Institute base. This was information he hadn’t offered on the phone, that he was Akhil’s boss, and it made me distrust him. I’d assumed I was being called by a liaison of some sort. The blankness of his office, not even any photos on his desk or generic art on the wall, added to this feeling.

“Can you tell me what happened with Akhil?” I asked, badgering my way through preliminaries.

“Of course. Take a seat.” He gestured toward one of the leather chairs in front of his desk. I sat down. Liam stayed standing behind me. “Liam, you may leave. I’ll buzz you when you can come back to escort Ms. Monroe.”

“Buzz me?” Liam said, with more than a hint of displeasure. But Spenceler had already written him out of the room and didn’t seem to notice. Liam nodded once at me as he left and said, “See you later, Dr. Monroe.”

As the door clicked closed, Spenceler lifted a remote control off his desk and pointed at the wall. A vid screen appeared. On the screen was Akhil’s face, staring into the camera.

“This was found in your brother’s belongings. It was labeled as a message for you.” He pressed Play and the vid came to life.

“I’m into something here with the Shadows,” Akhil said. The vid skipped for a split second. An error, or had something been erased? “The trees. When you look at the way the leaves are. There’s a story there.” Again, the vid skipped. I wondered if Spenceler had edited it. I assumed he had. I glanced at him but his face betrayed nothing. “And when I think about, I know that I need to go out there. I need to find them and talk to them. But, Alpha, the stars are out.”

The vid shut off. I stared at the black screen. Akhil had looked unwell. His normally perfect hair—something he’d half-jokingly and mostly very seriously prided himself on since he was a teen—was disheveled, and his eyes had dark circles surrounding them.

“Do you understand any of what he said?” Spenceler asked.

“Not much. I know a little about Shadows, of course. My parents were some of the—”

“Pioneers in the field. We were quite excited to work with Akhil because of that. Do you understand anything of the rest of the message or why it was left for you?” Spenceler’s gaze didn’t leave mine. He was waiting for me to give something away.

“Well, I’m his sister. His whole family, basically, now. So maybe that’s why? I don’t understand much else, though obviously we’re in a forest and I’m a botanist, so that might explain the stuff about trees.” I crossed my legs and kept eye contact with Spenceler. If he was looking for a flinch, he wouldn’t get it from me. “Now, I’d like to know what happened to him. Where you think he is.”

Spenceler sighed. “We don’t really have any idea. He was doing some fieldwork in the forest. Basic day-to-day, and he always returned at night. Then he didn’t. We tried to use his locator, but it was either turned off or broken.”

“Did you send out a team to look for him?”

“We did.” Spenceler broke eye contact.

“And?”

“They didn’t come back.”

At that, I flinched. “What?”

“That was almost two weeks ago. All of their locators disappeared from our radar.”

I took it in. Akhil had been gone for almost half a month. In a forest so large that anyone lost in it could conceivably never be found. In a forest where Shadows lived. Akhil, at five, turning to me with a grin and a frog in his hands. Akhil in the forest.

“Why did you bring me here?”

“Because we think you can find him,” Spenceler said.

When I was young, I used to believe that blood connected you. If I were honest, though, I’d admit that my belief had gone beyond a feeling of familial connection and into the realm of the supernatural. I used to believe that Akhil and I could sense each other. As if, across miles, we’d know what the other was feeling. Sometimes I thought that if I could just clear the static from the air around me, then I would hear his thoughts even.

When Spenceler told me what the Institute had created, it made me think I hadn’t been so wrong at all.

“We’re calling the prototype a Sangtraceur. We’ll change the name if we put it on market, but the scientists seem to like the duality.”

“Blood tracker?” I said. He had explained the device in vague terms, just enough so I’d know what I was getting into. Essentially, it was something I’d physically ingest, and afterward, if I got close to someone whose blood had similar genetic markers to mine, then I’d know it. He avoided explaining how I’d know, even when I asked, which made me nervous. It was always the “and other possible side effects” that were the worst ones in science.

“I don’t really understand how this could be marketed,” I said. “Wouldn’t it only work in situations where the missing party had a blood relative available to assist?”

“Technically, no. We’re working to develop it so that we could use a blood sample from the missing person. Unfortunately, we have no such samples of Akhil’s blood. At this point, it’s somewhat of a long shot even using you. We only thought to try because you’re twins.”

I was willing to try anything.

Only once had Akhil and I ever really talked about Shadows when he was at the Institute. He had come to visit me. I’d shown him around the lab, introduced him to all of my trees. Their scientific names and then the names I gave them that no one else knew about.

“Do you think the Shadows do that?” he asked me.

“Do what?” I was absentmindedly running a hand along the trunk of Portia, a small juniper.

“Personify things. Name them.”

I’d never wondered about the Shadows’ inner lives. Never even imagined them having any. So I just stared at Akhil. Waiting for him to go on.

“They must have dreams, too, right?” he’d said, but it wasn’t a question so much as a wish.

I ate in the base’s mess hall that night. Liam sat next to me, perhaps taking his chaperone duty a little too seriously.

The base’s food was exactly what I should have expected from a well-funded facility: the kind of cuisine found in fusion restaurants with three-star reviews, designed by people who didn’t understand the cuisines they were fusing. I hated it.

The way Liam stared at his plate made me think he had similar misgivings about chilaquiles made with a mint-and-seaweed mole. I was about to ask him when a blond woman walked up to me.

“You’re Akhil’s sister?” she asked.

I nodded. “Chetna.”

“I’m Rebecca Halprin. I was on Akhil’s research team.” She held out a hand for me to shake. I didn’t like her use of the past tense, but I shook her hand anyway. “I always wanted to meet you!” She said it brightly, but it raised flags for me. I could sense there was more gossip than interest behind her comment.

“What were you researching exactly?” I asked.

She stared at Liam for a beat too long, though he didn’t notice. “Ecosystems.”

“What about ecosystems?” I asked. She narrowed her eyes at me, as if to say Not in front of the help.

“I’m sure Akhil told you about it” was her measured response. She emphasized the “sure.”

I wondered if she knew how little Akhil and I had spoken. I thought she must have. She left, and I was glad to see her gone.

“They don’t like saying much around me,” Liam said. I hadn’t realized he’d been paying attention.

“Why not?” I asked.

“Probably because I’m not a part of the Institute exactly.”

“But you work for them?”

“No, not at all. I told you I did documentation and photography. I’m technically being paid by the government to document Trow’s progress. They’re required to have an outside, unbiased person to do the documentation. Something for their funding, I guess.” He shrugged. Maybe he was someone who didn’t like asking questions of life. It was possible he was the kind of person who knew that in some situations, the less interested you seemed, the more you’d be able to find out. But he didn’t come across as having a duplicitous side. “You know, there isn’t a lot for me to do, so they end up assigning me to random tasks. Pick this person up, look through these files for errors. It’s their dime, I guess.”

Was there really so little to document? I wondered if the government was worried about what the Institute was doing. I’d have been worried.

“Dad! Dad!” I’d yelled when I couldn’t find the Shadow in its box.

He came running, Akhil close behind him.

“It’s not in the box anymore,” I said. The panic made my voice come out alien—sharp and high-pitched, more girlish than I’d ever sounded, even as a child.

“We’ve had to move it, Chet, it’s fine. It just had to be moved back to the Institute,” Dad said, soothingly.

I’d dreamed it escaped, had hovered over my bed and stretched its fingers out to touch my face. In the dream, I’d been unable to move, to fight, as it caressed my cheek, smiling like the darkness. That’s why I’d come to check on it. The shock of it not being there made my heart thud against my chest. My pulse raced so hard that my throat hurt.

“What if it gets out and no one’s watching it there?” I asked.

My father placed a hand on my shoulder. “The Institute knows how to handle Shadows, Chetna.”

Later, that night, Akhil and I played crazy eights, which I rarely lost and so always wanted to play.

“I’m going to join the Institute,” Akhil said.

I looked at him. There was a conviction in his voice so solid that the words seemed corporeal as they came from his mouth. “Why?”

He studied his cards. “To keep us safe. From the Shadows. I’ll make sure they don’t get out, Chet.”

He was making a promise, and I was afraid that he’d keep it.

I couldn’t sleep. The base’s silence was so unfamiliar to me. I crept to the window of the room I was in, not wanting to make a sound, to break the noiseless night.

There were no stars out, reminding me that Akhil’s video had warned me of monsters. The darkness was absolute. I waited for my eyes to adjust, to get some sense of what was out there. The shapes of trees beckoned, darker than the dark. These were not my saplings, not the trees I knew and cared about.

For the first time, I wondered if Akhil could be alive out there. It was a question I hadn’t allowed myself. Whenever I had missed him over the past two years, I had comforted myself with the thought that he was alive, that I could sense him across miles.

But I couldn’t sense him then. It was like one walkie-talkie was too far away and all I heard was the buzz, the buzz. The buzz was better than silence, though.

In the morning, we set out. Spenceler was providing a small team to go with me. He didn’t say it was for protection, but I figured that was the purpose. I was surprised at the lack of fanfare, of planning. It seemed unlike the Institute to rush anything. Again, I wondered what they weren’t telling me about Akhil and about just what he was researching. Why the rush? The willingness to call someone in who didn’t belong to them?

The application of the Sangtraceur was simple, almost as painless as testing blood sugar levels. One prick. I’d imagined it would feel momentous, but instead I hardly noticed it.

The team comprised Liam and two others—a compactly built woman, Grace, and an unusually tall man, Samuel. Together they looked like a dance team in an absurd comedy. Grace was on the same team as Akhil, she explained, and knew the area we were heading into. Samuel was security, but I noted he lacked weaponry of any sort. I wondered if Trow’s security used something other than guns.

I wasn’t sure why they’d included Liam. It seemed unlike the Institute to have an outsider, and he had seemed slightly bemused when I asked why he was joining. The bending around protocol made me feel more off-balance than I expected.

Grace had an easy laugh about her, and I wondered why she was working for a covert scientific base instead of somewhere in the sun—a garden or some other place where her laughter wouldn’t have echoed so strangely. She talked about various trinkets of subjects as we walked.

We had to walk—the trees were too dense to drive through—and dead leaves crunched beneath our feet. Something about the trees bothered me.

“I’ve always been a fan of boba tea, but your brother hated it. I suppose you know that, though,” Grace said. How we had gotten onto tea, I wasn’t sure, but my mind sprang back into the conversation at the mention of Akhil.

“He did? I don’t know that we ever really talked about tea much.”

“He said he had an aversion to things that felt like frog eggs—as if he knew how frog eggs felt.” She let out yet another peal of laughter.

“He did, though,” I said, smiling.

We must have been only four or five and walking in the woods behind the house. There was a stream that ran through it—a gentle one that we could cross without worry of getting tossed about or pulled under, so our parents trusted us to walk near it by ourselves. Once, we’d spotted a clutch of frog eggs between some stones and we’d both been fascinated. Before I could say anything, Akhil had reached out and grabbed up an egg from the edge of the mass. Then he walked back toward me to show me.

But he was small and didn’t know how to hold things, and the egg was smaller and didn’t know how to be held. Somewhere in the steps back to me, it had slipped through the cracks in between his fingers, fallen back into the water, been pushed along the stream. When Akhil realized, he let out a soft “No.”

We looked in the water, tried to find it, to return it to its siblings, but the egg was gone. Akhil had stared at the water with such a look of loss. At the time, it had felt larger than I could carry.

We had been walking for hours, and I had felt nothing. Maybe the Sangtraceur was a faulty experiment. Maybe my blood wasn’t strong enough. Maybe some connection was lost. I wanted to pause, to lean against a tree and just think for a moment. But the tree trunks all looked less inviting than my trees back home.

Grace and Samuel had gotten ahead, were talking quietly. Once in a while, Grace would nod and glance back at Liam and me. Were they talking about things they didn’t want us to overhear?

“The trees are bothering me,” Liam said.

“Me too. Something’s off, and I can’t place my finger on it.”

“Same. It’s like I’m seeing every bit of the puzzle but not the picture it’s supposed to make.”

It seemed to be getting darker. I wasn’t sure if it was because it was later in the day than I realized or if the trees were becoming even denser. While dense forests often had more foliage, as trees needed to drink up the light in any way they could, the branches and leaves here went further down the trunks than seemed quite right.

Liam paused. He bent to the ground and picked something up with a frown.

“What is it?” Grace asked. She and Samuel must have paused and noticed us dawdling.

He held out the object that he’d picked up. A red cherry, stem and leaf still attached. “This seems…out of place.”

I looked up and understood why the trees had been bothering me. Earlier it hadn’t been as obvious. The variations had been only slight: birch with bark a little less smooth than it should have been. But here the deception was failing completely. The leaves were wrong. The trees were wrong. A few of the tree trunks looked like species of pine but had leaves—oak leaves and plum leaves. Fruit hung alongside pine needles on other trees that had the trunks of oaks. The trees were all wrong. “What the fuck…”

“What?” Samuel asked.

“The trees—” I began.

Liam cut me off. “They’re mixes. Impossible mixes.”

As he said it, I felt something strange. It was like something was moving inside my veins—a pulse that wasn’t my own pulse, traveling through my body, slowly getting stronger. If I had to name it, I would say that my blood felt like it was screaming.

Grace frowned and walked up to the nearest tree, a pine. She reached out to touch the trunk. As she did, a burning sensation hit me in the head. It felt like a migraine bursting into life, but more intense and instantaneous than any I’d ever had before. Other possible side effects, I thought for a split second before the pain seemed to rip open my skull.

On my knees, without realizing I’d fallen, I clutched my head.

Liam rushed to my side. “What is it?”

I couldn’t see through the pain. Only flashes of light. Then I heard someone scream, and I wasn’t sure that it wasn’t me.

As the world soared into darkness, I thought I saw the trees bending toward our group, as if reaching down to grab us.

In my dreams, my mother often braids my hair. I haven’t kept it long in years, but still in dreams, she can braid it. She tells me stories about Shadows. She says, “Don’t be afraid, Chetna.”

In the mirror, my Shadow smiles at me.

In my father’s office, he kept drawings people had done of Shadows. He told me, “Maybe they’ve always been here. Every culture tells stories of people who aren’t people—the fair folk, the angels, the women who slip out of the river at night. Maybe that’s always been them.”

I was so afraid.

Akhil tells me, “If we can map them, then we can understand them.”

There are so many things we’ve never been able to map completely: the bottom of the ocean, the brain while it dreams, other planets.

My mother smooths hair back from my forehead. She says, “You’re safe.”

Opening my eyes, I wasn’t sure how long I’d been out. Above me, the trees seemed to stretch up forever. I rolled over onto my side and came face to face with Grace. Her eyes stared blankly back into mine. I held in a scream, jumping to my feet. Grace’s body looked fine, as if she were just watching clouds. Her face, though, was like an absence. Her eyes wide and not seeing. Her mouth was opened, slightly, as if she were about to speak but had no words. Samuel and Liam were gone.

“Liam!” I yelled, hoping for but not expecting a response.

Silence. And then, “Chetna!”

I spun toward the sound. Liam was sitting against one of the trees, a couple dozen yards away. I ran to him. His face was pale and his breathing shallow, but he was alive. “What the hell happened?”

He shook his head. “You went down, and then Grace was screaming. It looked like…”

“Like?”

“Like a tree branch had grabbed ahold of her. It squeezed her until she just stopped moving. I don’t know where Samuel went. I think something hit me.” He winced, the talking aggravating whatever injury he had.

“Okay, we’re going to get out of here.” I helped him to his feet, glad for my height and build as he needed to lean heavily against me. “Can you get us back to the base?”

He nodded, groaning as he did so. We moved as quickly as we could, the forest growing darker around us. I listened for any sounds that might be Samuel. There was nothing.

“Why were the trees wrong?” Liam asked. “How was that possible? Trees don’t just—”

“I don’t know. Don’t talk, save your energy.” I didn’t say what I was thinking, remembering that Shadows had learned to mimic the looks of people. Why couldn’t they have learned to mimic the looks of trees? Why couldn’t they be spying on a base that was supposed to be spying on them?

It felt like we had walked for years, but I finally began to recognize that we were getting closer to the base.

Liam saw it first. “Oh fuck, fuck, fuck.”

The base was gone. Or not gone, but overgrown. Tree branches burst through the windows, grew out through the roof. Hundreds of trees. There were still vehicles outside, though. Only a single Jeep hadn’t been overturned by roots.

We made our way toward it, and as we got closer, I could feel the tingling in my veins again. That pulse, pulse, pulse that was both not my own and yet as familiar as a voice I’d known since the day I was born. I needed not to give in to it. If I dropped from the pain, then Liam would be stranded as well as me.

Pulse. Pulse. Heart beating so hard that I could feel it through my own palm when he had held my hand after the fall. Two pulses, racing at the same tempo.

Then I saw the body. I thought it was someone from the base. Except there was something so familiar about the curve of the body, the hair. “Akhil!”

I wanted to run, but Liam couldn’t, so we limped closer. Akhil looked peaceful, eyes closed, but his clothing was ragged and filthy. There was a scream in my throat that I couldn’t let go of.

Then his chest rose, once. He was breathing. Shallow, hiccupping breaths, but he was breathing.

I got Liam to the Jeep, and then I went to Akhil. His eyes moved beneath the lids. He was dreaming. I dragged him toward the Jeep, managing to get him inside. Liam said he could drive, though he looked like he was fooling himself. I let him, wanting to sit by my brother, make sure he stayed breathing. Listening to his breath, it sounded like the safety of home.

The Institute told me that no one was left alive on the base. They didn’t go into details, for which I’m thankful. What the Institute said was that Spenceler had gone off the grid. He was supposed to be mapping Shadows, but he’d decided to try and capture them instead. The forest as some kind of perimeter he could control. They said they sanctioned nothing. I didn’t believe them. I think they knew that I didn’t. An anonymous donation of funds was sent to my research team the day after the call. Enough to help us through a few years of dedicated study, at least.

Liam and I kept in touch. He asked me once, when he was in the hospital still, if I thought the Institute had had him accompany me because they were hoping to get rid of him. I’d wondered the same thing, or if they were hoping he’d convince the government to increase their funding. The dead can tell us nothing, though, and so I shrugged and said, “Maybe they just wanted me to feel comfortable.” And we both laughed at that.

He left the government and began to work as a photojournalist. His work surprised me, capturing light and dark in new ways. He would’ve been good at photographing Shadows, but I don’t think he’d like to hear that.

Akhil slept. He continues to sleep. Doctors tell me that he might never wake up. Comas are strange. Sometimes a person wakes up after ten years, or ten days, and sometimes they never wake up, just eventually go from one kind of sleep to another.

I may never know what he discovered. I may never hear him tell me the stories of what happened to him. Any stories. He had figured out the leaves, but why did he go back out into them? Still, I think the Shadows returned him to me. They hadn’t killed him. That said something, but I wasn’t sure what.

Occasionally, I’ll catch a glimpse of my reflection in a darkened train window, a bathroom mirror somewhere the lights aren’t shining bright enough, and my reflection will smile back at my frowning face. I never know if they’re watching me to see if they made the right choice, or if they watch everyone and I’m the only one who knows to notice. When I can, when there’s time before the tunnel opens, before the light pulls my reflection away, I’ll stare back. I wonder if it scares them when I smile, too.

Often, I visit Akhil in the hospital. I sit by his bed and tell him about my life, about the research into Shadows being done, the advances made. Mostly, I end up watching him breathe. I don’t know if I’m cutting through the static at all, but still, I tell him, “I’m here, Bravo, I’m here.”