I WAS NEVER meant to be in the FBI. My life started out on a completely different path.

I grew up in a little town in Wisconsin. My mom was a seamstress and ran a dress shop selling her handmade dresses. My dad was an artist who painted landscapes. We weren’t rich, but we were happy, and lived in a rickety old house with a big garden that backed onto fields. I ran around barefoot in grass that came past my knees and made friends with the rabbits and birds. My mom was pretty, with long golden hair, and my dad had a prickly, dark brown beard and played the guitar under the stars. When I painted pictures of our family at kindergarten, I always knew I could make the color for my muddy brown hair by mixing their two hair colors together. I got my freckles from my dad, and my short sight. But I didn’t inherit his artistic ability. No matter how hard I tried, I couldn’t paint like him. “You just haven’t found your thing yet,” he used to tell me. “You will.”

Then one night, when I was eight, my dad went out to pick up milk and didn’t come home. The police arrived an hour later to tell us he’d been shot dead by a guy who’d robbed the convenience store.

It was like my mom’s heart had been ripped out. For two years, she got thinner and paler, and I got more and more worried about her. Then a guy called Tanner stopped at the dress shop to ask directions, and everything changed.

They went out for three nights in a row, but then Tanner had to go: he lived in New York and had only been passing through. A week later, he was back, and then it was every weekend, and that unsettled me because I wasn’t sure I trusted this guy. He drank, and he made jokes about everyone in our little town being bumpkins. And when he got mad, he’d yell and curse and kick stuff in a way that scared me. But my mom’s face lit up whenever she saw him and I just wanted her to be happy. So I smiled and kept quiet.

Six months later, they were married. We sold everything except my dad’s paintings and moved into Tanner’s cramped New York apartment. The first evening, Tanner took us up to the roof, holding hands with my mom and grinning as we looked out over the city, but I remember feeling sick. Not just from the drop—I hate heights—but from the endless gray blocks around me. I couldn’t see any green anywhere.

I hated my new school: I was the weird country kid. The only nature was a tiny neighborhood garden where the grass was yellow and crunchy, as if the city was making it ill, and all the kids stared at me when I took my shoes off.

Pretty soon, we realized that Tanner was into some bad stuff. He dealt some drugs and the apartment was full of stolen stuff he was trying to sell. He wasn’t good at it, though, losing more money than he made. My mom opened a dress shop and somehow made it work, even in that lousy neighborhood, but there was still barely enough money to pay the rent. Then she got ill and the doctors diagnosed her with lupus. When it was bad, she couldn’t work and money became even tighter. Tanner turned sour and resentful: his four nightly beers turned into six and then eight. He’d get wasted and yell at her.

And then the yelling turned to hitting. Black eyes she tried to hide with make-up. Cracked ribs that made it painful to breathe or talk. I hid in my room and looked up at the magazine pictures I’d used to paper the walls, far-off places like Colorado and Alaska, full of green and blue, and I tried to dream myself there.

When I was ten, my mom tried to leave him and run back to Wisconsin. Tanner caught us halfway and put my mom in the hospital, and told her he’d kill both of us if she tried to leave him again. He’d failed at being a criminal, failed at being a provider. He didn’t want anyone to know he’d failed at being a husband, too.

A few weeks after that, Tanner rolled in drunk and collapsed into his armchair. He yelled for my mom to bring him a beer but she was in bed with a bad flare-up of the lupus, barely able to walk. I was in their bedroom, looking after her, and I saw her struggle to try to get up, gritting her teeth in pain—

“No,” I told her, tears in my eyes. “No.” And I pushed her back into bed and went out into the hallway, ignoring her protests. I went to the refrigerator and I brought Tanner his beer.

When he saw it was me, he cursed me, saying I was just as much of a waste of space as my mother. And when I got close enough, he hit me for the first time, an open-handed whack across the face that shook my teeth and made me see stars.

But from that night on, I brought him his beers and food, and cleaned the house. Anything to keep him away from my mom, who was getting sicker each day.

He hit me. He kicked me when I was down. Once, when I was thirteen, I dropped a hot skillet and it left a scorch mark on the linoleum. Tanner picked it up, pulled up my T-shirt, and pressed the hot edge of it against my side to teach me a lesson. I heard my skin sizzle like steak dropped into a pan. I knew I couldn’t go to the ER, so I treated the burn myself, and I still have the scar. It did teach me a lesson, though. The less he saw and heard me, the less he hit me.

And so I became invisible. My self-confidence disappeared. Every day, I heard how worthless I was, the words driven into me with his fists. He laughed at my dreams of green, faraway places and ripped down the pictures I’d taped to my walls. I was glad I’d hidden my dad’s paintings at the bottom of my closet or they would have been destroyed or sold. I retreated into myself, dressing in shapeless hooded tops and jeans, making myself as neutral and easy to ignore as possible. Boys looked right past me. Teachers forgot I was even in their class. I took a job at a grocery store to help with the bills: my mom was barely able to keep her store open, she was sick so much.

When I was eighteen, I went up to the roof of the apartment block. I was so lonely, so beaten down, I was at the point of jumping. But I was worried about my mom. If I left her alone with him, he’d start beating her again.

That’s when I saw it, balanced right on the edge of the roof. A bird’s nest, with a mother bird perched on the edge, feeding her young. It was the most beautiful thing I’d ever seen, and I was so close: the birds were completely unaware of me.

And I realized that my invisibility was good for something. I was so quiet, so unobtrusive, I could get closer to animals than anyone else.

I started to head out into the city, slipping unnoticed through abandoned buildings, finding bats and stray cats and mice to watch. Being around those little bits of wildlife was just enough to keep me sane.

One day, exploring a derelict factory, I found I wasn’t alone. An old African-American guy, his hair gunmetal gray, was photographing the birds I was watching. I was cautious at first. I was amazed someone had even noticed me. But he was friendly and, over weeks and months, we became close. His name was Rufus and, back in the day, he’d been a war reporter. His apartment was covered in yellow, faded photographs of Iraq, Kuwait, and Sarajevo. He gave me one of his old cameras and, from the first moment I tried it, I was hooked. My invisibility meant I could get close to the animals I loved, and the camera meant I could share what I saw with the world. A few weeks in, Rufus looked at a photo I’d taken of a nest of newborn mice, cuddled up together for warmth. One had opened his eyes and peeked up at me and, reflected in those big, black orbs, you could see the New York skyline, the big bad city they were about to go out into. “You’re a natural,” Rufus told me. “You have an eye for detail.”

I’d finally found my thing.

For two years, my life was protecting my mother at home, working at the grocery store to earn money for rent, and a few precious hours each day learning from Rufus. He asked about the bruises and I knew he was mad that someone was hurting me. But I also knew Tanner would kill him if they fought, and Rufus was becoming like a father to me, so I kept quiet.

Then, when I was twenty, Tanner died, stabbed in a bar fight. I knew I should be sad, but all I felt was relief, which made me wonder if I was a terrible person. I thought my life would change, but my mom and I were still stuck in New York: we didn’t have the money to risk shutting down my mom’s store and re-opening it back in Wisconsin. So I kept working, learning, looking after my mom, hoping one day I could get somewhere green again. I dreamed of becoming a wildlife photographer.

One night when I was at Rufus’s apartment, there was a yell from outside. One of the local dealers was beating up a woman, right outside the door. When Rufus went to help, I grabbed his arm. He was almost seventy, for god’s sake!

But he turned to me, one hand on the doorknob, and said, “Someone has to do something.”

And before I could stop him, he ran outside and pulled the dealer off the woman. They rolled on the ground together, then the dealer got on top, raising his fists….

By the time the cops arrived, the dealer had run and so had the woman. And my friend and mentor was lying dead on the ground. The cops knew the dealer: everyone in the neighborhood did. But they claimed there wasn’t enough evidence to bring him in. The truth was, they’d been taking bribes from him for years.

At Rufus’s funeral, I was the only mourner. I stood there with rain mixing with my tears, the hot, bitter injustice of it filling me from the inside out until I thought I’d explode.

I wasn’t brave. I was no one.

But someone had to do something.

So I took my camera and packed a bag with food and water. And for three days straight, I followed that dealer like a ghost, hiding in alleys and on rooftops, documenting his every move. My eye for detail let me get the little things that would make a difference: the scratches on his car that proved it was his, as he pulled away from picking up a package of drugs. The tattoo on his hand, as he handed over bribe money to the cops.

I sent the photos to the head of the Vice Unit, going over the heads of the bribed cops. A few days later, the dealer was arrested. But another dealer moved into his territory. People were getting hurt. Kids were being recruited to sell on street corners. And no one else in the neighborhood could do anything.

I began to take them down, one by one, hiding in the shadows and getting the photographic evidence the police couldn’t and sending it anonymously to the Vice Unit. In six months, I helped bring down four dealers. I bought a burner phone that couldn’t be traced back to me and gave the number to the police in case they needed to ask for more pictures of someone. But when it rang, it wasn’t the police. It was a woman called Carrie Blake, and she worked for the FBI. She persuaded me to meet and, over coffee, she asked me if I’d like to come and work for them. “You have an amazing eye for detail,” she told me. “And you get shots no one else can. How would you like to bring down some really bad guys?”

I knew I was nothing like an FBI agent. I wasn’t brave, or heroic. But my mom’s medical bills were piling up and the FBI paid a lot better than the grocery store….

So I went to work at the FBI’s New York office as a specialist and met Sam Calahan, and Alison, and Gwen and Kate, and they were real FBI agents, cool and confident field agents who kicked down doors and pointed guns—even Kate, who was only a little thing of 5’2”, but could take down a bad guy better than anyone. They tolerated my quietness and they all became friends, especially Kate, and I really missed her when she moved to Alaska.

Carrie became like a second mother to me and I worked hard, surveilling anyone she pointed me at. In my first year, I got the goods on every bad guy I was told to watch. I was good at my job, but I was still hiding behind a camera lens, invisible... and very, very lonely.

Then one day, Carrie showed me a grainy black-and-white photograph of the most gorgeous man I’d ever seen. This is Konstantin Gulyev, she told me. And you and I are going to bring the bastard down.

For two years, I tried to do exactly that. I watched his every move, listened to his calls, but he was too smart, too careful: I couldn’t get the evidence we needed to bring him down. And I started to find myself drawn to him. I couldn’t understand why. He was a criminal, and criminals had killed or hurt everyone I’d ever loved.

Then there was Boston, and what happened in his hotel room.

And now, everything was different.