To wit, she has no apprehension about tonight’s task. She decided to crash an underground MMA fight with zero hesitancy. Her psychopathy dictates her fearless nature. She doesn’t experience fear the way most do. Rather, she observes it, as if it’s a secondhand emotion, only there to sharpen her senses.

I blow the debris off the knife. The four-inch steel doesn’t appear deadly—but the damage it can inflict is lethal. I flatten the blade against my forearm to test the edge. Shave off a layer of hair and dead skin cells. Just like that, so mindlessly, my DNA becomes a part of the room. Dead cells shed to make way for new growth.

How much of Blakely is dead?

Tonight, I test a theory.

Hypothesis 1: Faced with violence, Blakely will a) resort to violence herself, and b) will use me as an instrument for that violence.

Assessing the outcome will help me gauge her ability and the preparation I need to make.

I sink the hunting knife into the black leather holster and strap it to my ankle. A couple years ago, the thought of violence in any form would’ve made me cower. I was repulsed by the Neanderthals that demonstrated this kind of barbaric retaliation.

But…life has a way of testing us. Making us reevaluate our belief systems. I’ve embraced a primitive ideology that the strong devour the weak. Survival of the fittest. And any other cliché that fits.

A text from Blakely appears on my screen:

Time to go. Meet me at the station.

I pocket both phones before I head toward the door. Tonight, I make a detour. Before I touch my twin sister’s picture, I pause at the armchair. I bring the pillow to my nose and inhale deeply. Blakely’s fragrance of sweet coconut milk and bergamot consumes my senses. I can taste her on my tongue as I leave my apartment.

Vengeance has a scent, and it smells like Blakely.

Rust claws up a gun-metal gray warehouse set along the East River. Lights from the prison on Rikers Island glow in hazy blooms of yellow and orange against a midnight-blue sky. The earthy aroma of fresh rain and acrid mildew mix with the night air to ground me in the moment.

It’s quiet here on the edge of the city, denoting a sense of solitude, even though a herd of people gather in front of the meat-packing warehouse.

Before we arrived, Blakely and I waited near the number 2, growing impatient when Ericson still hadn’t received a text for the fight location. It finally came through fifty minutes ago. According to Blakely, these fights change location, never happening in the same place twice in a row.

We took the train to the Bronx, then a cab dropped us off one street over. She wanted to get a look at the place from a distance, watch people as they arrive. We stand across the street now as Blakely eyes the cut bouncer standing guard at the entrance to our destination.

Tickets for the fight are sold in advance through covert channels—channels we don’t have access to. “What’s the plan to get inside?” I ask.

She scans the crowd, then nods to a guy wearing a puffer jacket standing in the back of the forming line. “Let’s talk to him.” She sets off, but abruptly stops and holds up her hand. “Wait.”

She faces me and places her hands on my chest. She’s a few inches shorter than me, even in heels, and that distinct fragrance that is all her envelops me. A distraction I try to overcome as she moves her palms down my body.

“You change your mind quick,” I say, affecting a smug tone.

Then I realize she’s patting me down. I try to step away, but she drops down and hikes up the cuff of my jeans. With deft reflexes, she snatches the holster off my ankle.

As she gets to her feet, she unsheathes the hunting knife. “Christ. Who are you, Rambo?”

I tense at her chiding remark. “I thought we might need protection.”

She arches an accusatory eyebrow. “I am the protection,” she says. “Besides, you can’t take weapons into a place like this. They search you. And when that meaty bouncer over there finds this knife, he’ll toss you out. Very painfully.”

“Duly noted.” I watch her discard my knife in a trash bin with a sharp stab of pain to my gut. “How did you know I was carrying?”

“Carrying?” Her full lips twist into a sardonic smile. “You’ve been walking odd tonight, favoring one leg. And you kept looking down at your ankle on the ride here.” She shrugs, like this skill is nothing at all.

But to me, it’s everything. It’s a part of the equation; one of the necessary variables to help solve the problem.

She hovers close to me, and I’m drawn to the hum of her skin—that crackle of chemistry between us. “You wore your contacts,” she says. “Good.” Then she drives her fingers into my hair to muss it up. “But better. Now untuck your shirt.”

With barely constrained resentment, I do as instructed, trailing behind her as she approaches the lone straggler at the back of the line. I’m supposed to be playing this part…the shmuck…and yet, Blakely makes the role feel all too real.

“We need tickets,” she tells the guy.

He scoffs and looks around. “Sold out, baby.”

“How much?” she insists.

He sniffs hard and sinks his hands into his oversized jacket. Then he looks her up and down. “I only have two,” he says, “five-hundo a piece.”

Blakely doesn’t blink as she reaches into her cross-shoulder bag and produces a zip pouch. She counts out the cash, and the guy reaches for the wad. “Show me the tickets,” she demands.

He shrugs into his jacket and pulls out two tickets which, surprisingly, look to be professionally printed. They make the trade.

As we move toward the line, I look at her. “How did you know he had tickets?”

“Shit, you ask a lot of questions.”

I do. I make a note of that, as I don’t want her to get even more suspicious of my motives. “Just curious.”

“You just get to know these things when you deal with people,” she says.

I’m sure this is true, to some extent. But there’s a reason why certain people take particular career paths. Detectives, investigators, politicians. They have attuned instincts, and an innate ability to read people.

Empathy plays a part.

For Blakely, this skill isn’t so much innate as it is learned. Developed and honed.

There are two kinds of empathy: cognitive and emotional. Cognitive empathy is the ability to understand what others are feeling. Emotional empathy is the capability to feel what others are feeling.

There’s a decisive difference.

Cognitive empathy in the hands of a psychopath is a dangerous device. They can read a person, suss out their vulnerabilities, and use those vulnerabilities against them.

From what I’ve observed, Blakely has remarkable cognitive empathy. So remarkable, in fact, she’s able to use people’s emotions to manipulate them and the situation.

Mary had journals filled with insight into this characteristic, and I’ve studied them cover to cover. My sister was an expert in her field, much like I am in mine. I never appreciated how much psychology and science intersected until she was gone.

It’s too late to tell her now.

We reach the front door of the warehouse. The burly bouncer with a neck the size of my thigh winks at Blakely as he accepts our tickets. He overlooks me and talks directly to her. “You want to be a card girl?” he says to her. “We have an opening.”

I might as well not exist. That, or these men don’t find me a challenge. I’m not any sort of imposing obstacle to Blakely.

“I have a job, thanks,” she says. “Just here to enjoy the bouts.”

He grunts and nods at her, apparently approving of her response. Maybe it was a test; has she ever been to a fight before? As I scanned the crowd earlier, I mentally calculated around sixty people. People that are probably return customers.