My name is Winter Kim. Today I killed a man. Soon I hope to kill another.

As the MetroLink train shimmies along its metal tracks, I repeat those words over and over in my head. I recently found out my sister, Rose, was murdered. Her ex-boyfriend, Gideon Seung, suggested we attend a bereavement support group together. But before I could even think about that, Gideon was killed too. And then I killed his killer.

I close my eyes and envision telling a room full of strangers that the only two people I loved were both murdered. There would be the obligatory sympathetic cooing and perhaps a gasp of shock. Then I'd tell them I'm a killer too and I'm not finished yet. The expressions of bland disinterest would twist into disgust. The woman who comes mostly for the free food would choke on her coffee cake.

You're a monster, she'd whisper, before quickly averting her eyes.

Maybe I am a monster.

As far as I know, there's no support group for that.

The train hisses slightly as it pulls into the next station. Snowflakes batter the windows, sticking fast to the cold glass in tiny deformed clumps. Beyond the platform, the streets of St. Louis stretch out empty and cold. And dark. It's only six P.M., but it might as well be midnight.

A man pushing a metal cart ducks through the open doors, the wheels leaving trails of grayish sludge on the patterned floor of the train. He takes a seat across from me and folds back the lid to his trolley, exposing items for sale — perfume, neckties, designer purses. The strange combinations of what people sell on the train remind me of the subway stations back in Seoul. You could buy almost anything there.

The train starts moving again. The man steps out into the aisle and begins pushing his trolley toward the front of the car, stopping occasionally to address specific passengers. Turning toward the window, I pull an envelope out of the center pocket of my hoodie. My name is written on the front in black ink. My eyes water as I consider Gideon's neatly printed capital letters. I'll never see that handwriting again.

I run my thumb along the flap of the envelope and the paper slices into my flesh, leaving behind a thin trail of red. I lift my hand to my lips and taste the metallic flavor of blood. My fingers brush against the rose pendant that hangs in the hollow of my throat. The necklace used to belong to my sister.

I wrap my fingers around it, grip it so tight that the metal cuts into my palm. Rose died so that I could escape our past.

And now I am free.

But alone.

Vengeance is all that I have left.

Monster, a voice hisses from inside my brain.

Monsters don't get happy endings.

* * *

The train reaches the end of the line — the airport — and I stay tucked in my seat as the other passengers disembark. A pair of security agents passes by in their navy uniforms, followed by two teens in NFL parkas. After them, a group of people wheel suitcases up the wet floor, most of them looking down at their phones as they trudge along. Finally it's just me and the man with the trolley. He gestures at me and I slide out of my seat. Behind me, his wet, metal wheels bump into the back of my ankles. The man grunts an apology. I nod an acknowledgment without looking back.

Outside, the sharp air cuts through my hoodie and the T-shirt beneath. I exhale a puff of white, half expecting the droplets of my breath to freeze and fall to the ground like a tiny ice storm.

"Cold, huh?" Trolley Guy says as he slides past me. A dark red necktie dangles from the top of his rolling cart.

"Yes." My voice is barely audible. My eyes home in on the red slash of fabric. I am thinking about the man who took everyone I love away from me. Kyung. His name is a knife blade, but I'm done being stabbed by it. It's my turn to inflict the damage.

The red tie vanishes from sight as Trolley Guy disappears behind a pillar. Kyung wore a tie that color the first time I met him. Rose and I stood side by side in the center of a room while he evaluated us like we were farm animals. Not exactly what I was hoping for, but I guess they'll do. My sister's face burned with shame as he circled us, touching her hair, lifting her skirt to examine her legs. I didn't understand what was happening yet, but she did.

A set of sliding glass doors opens and the stream of people funnels me into the airport and up a set of narrow escalators. I glance back at the MetroLink tracks through a wall of glass windows. It was probably foolish of me to come here. I don't even have any luggage — no place to check my knives and hide my spare IDs.

I couldn't go to my therapist appointment, though. If I had, I would've broken down and told Dr. Abrams everything. She would have been obligated to put me in a psychiatric facility and warn Kyung that I had threatened his life. Plus, she would've gone to the police and they probably would have figured out what really happened in the penthouse.

What really happened is this: Kyung sent a man named Sung Jin to coerce Gideon into giving up the ViSE technology. Gideon tried to refuse and Sung Jin killed him. Sung Jin also shot my friend Jesse Ramirez and Gideon's head of security, Baz Faber.

And then I killed Sung Jin.

I should probably feel something when I think about that, when I think about pulling the trigger on the gun. When I think about his sharp, mercenary eyes turning to black glass. It's no small thing — ending someone else's life. There should be some sort of gravity to that, shouldn't there? My insides are heavy, but it has nothing to do with what I did. It is only about what I have lost.

I take a seat in the ticketing and departures lobby and watch travelers mill back and forth, their suitcases trailing behind them like obedient toddlers. A cell phone buzzes in my pocket. Sung Jin's phone — it's a text from Kyung.

Kyung: Should I arrange for a car to pick you up at LAX tomorrow?

Me: Tomorrow is too soon. Gideon told you the ViSE technology was stolen, right? I know who has it but reacquiring it will take time.

I actually have both the neural editor and recorder headset that Kyung wants me to bring him. Gideon lied to Kyung and said they were stolen to try to buy more time to figure out how to protect the technology. I'm hoping I can use his lie to my advantage.

Kyung: Two more days.

Me: That's not enough. I need a week.

Kyung: Five days. Bring the tech to me at UsuMed by Wednesday, or else.

Kyung and I have struck a deal of sorts. He claims I have a younger brother, Jun, who works for him, and that if I turn over Gideon's ViSE technology, he'll introduce us. ViSEs, or Vicarious Sensory Experiences, are neural recordings that allow a person to experience an activity via someone else's brain — all the thrills of rock climbing or bungee jumping or running from the police with none of the risk. I don't know what Kyung wants with the tech, but he wants it badly enough that he's threatened to kill Jun if I don't hand it over.

I hate that I'm risking my brother's life — assuming he's real — by not turning over the tech immediately, but I'm fairly certain Kyung is just trying to intimidate me. He won't really hurt my brother, as long as I don't push him too far. If he does, then he'll never get what he wants.

I switch to a browser window and do a search for "Jun Song" in Los Angeles. There are several...