Chapter 7: The Neuroscience of Desire
The lab was a cathedral of quiet thought after nightfall. I’d come to return a borrowed textbook—The Psychology of Attachment—that I’d found tucked under my arm after the Poli Sci lecture Scarlett and I had attended together. She’d said nothing, just slid it to me with a raised eyebrow. Finding her here, in her natural habitat, felt like the next logical step.
I found Mary Zhou instead.
She was leaning against the central EEG station, her arms crossed over a sweater adorned with cartoon brains. “Vy,” she said, her voice a cheerful ping in the silent room. “On a pilgrimage to the source?”
“Just returning this.” I held up the book. “Is Scarlett here?”
“She’s doing a data run. Be about fifteen minutes.” Mary pushed off the console, her eyes sharp behind her glasses. “You can wait. Maybe help me with a calibration.” Her smile was wide, but it didn’t reach her eyes. This was Katy’s other best friend. The calculus was immediate and cold.
“I shouldn’t intrude on lab time.”
“Nonsense. You’re practically a research subject by association.” She gestured to the chair, a sleek, reclining thing surrounded by a halo of wires and sensors. “Come on. I need a baseline for a non-cogsci major. It’s painless.”
The insistence was a wall. Saying no would be a retreat, an admission of something. I set the book down and took the seat.
She moved with practiced efficiency, cool gel touches on my temples, the careful placement of electrodes. Her fingers were deft, impersonal. “So. You and Scarlett.” She didn’t look at me, focusing on a monitor.
“Is that a calibration question?” I kept my voice flat.
“Just making conversation.” She tapped the screen, and a cascade of sine waves appeared, pulsing gently with my own rhythms. “It’s interesting. Scarlett’s work has taken a new direction lately. More affective neuroscience. Less pure game theory.”
She swiveled another monitor toward her, calling up a different file. The screen filled with a complex 3D model of a brain, rendered in electric blues and violets. “Like this. Her latest side project. Mapping neural correlates of… let’s call it ‘focused attention.’” Mary’s fingers flew over the keyboard, and the brain model began to play a time-lapse sequence.
I watched, mesmerized despite myself. The visual cortex lit up first, a bloom of color. Then the temporal lobe. Then, strikingly, a sustained, brilliant firestorm in the prefrontal cortex.
“Subject is shown a series of neutral and salient visual stimuli,” Mary narrated, her tone clinical. “Standard stuff. Faces, objects, text.” She pointed as a string of words flashed on a secondary screen: Apple. Tree. The. Vy.
My own name, in simple text.
On the brain model, the reaction was violent. Not just a light-up, but an eruption. The prefrontal cortex, the seat of executive function, of decision-making, blazed with such intensity it washed out the other colors. The amygdala, the fear and emotion center, showed only a mild, secondary flicker.
“See that?” Mary murmured, her voice dropping. “That’s not limbic system chaos. That’s not infatuation. That’s… recognition. Evaluation. Acute, sustained cognitive engagement.” She turned to me, her smirk gentle but precise. “Scarlett’ prefrontal cortex lights up like a supernova when you walk in, you know. Or even when your name appears. The data doesn’t lie. She’s not just feeling you, Vy. She’s processing you. At maximum capacity.”
I stared at the frozen image, the ghost of my name on the screen beside that spectacular neural firework display. It was the most intimate and alien thing I’d ever seen. My entire history with Katy had been lived in the limbic system—a swamp of fear, longing, and dopamine. This was different. This was a scan of the mind, not just the heart. It was terrifying in its clarity.
“Why are you showing me this?” My throat was tight.
“Call it professional curiosity,” Mary said, adjusting a dial. “Katy, she’s all heart. All impulse. It’s beautiful and destructive. Scarlett is all mind. Or she was.” She looked at me. “Now, you’re a variable that recalibrates her entire system. I find that scientifically significant.”
The lab door hissed open.
Scarlett stood there, a tablet in her hand, her wavy hair slightly damp from the evening mist. She took in the scene: me in the chair, wired up, Mary leaning over the monitor displaying her own private research.
The change on Scarlett’s face was instantaneous and total. The usual composed mask, the analytical calm, shattered. A flush of pure, unmitigated color rushed from her throat to her hairline. It wasn’t a blush of embarrassment; it was a systemic reaction, a total breach in her defenses. Her eyes went from Mary’s pleased smirk to the screen, then to me.
She looked genuinely, profoundly exposed.
“Mary.” Scarlett’s voice was a low wire. “What are you doing?”
“Just running a baseline,” Mary said lightly, standing up. “And showing Vy some fascinating comparative neural topography. Your work is really evolving, Scar.”
Scarlett didn’t move. The tablet hung limply at her side. For a long moment, the only sound was the hum of the machines, singing the song of our static.
“You can disconnect her now,” Scarlett finally said. The words were measured, but a faint tremor ran beneath them.
Mary began to carefully remove the electrodes, her touch now feeling intrusive. The cool air on my temples was a relief. I sat up, my eyes locked with Scarlett’s. The blush was fading, leaving behind a stark vulnerability I’d never seen. She looked younger. Uncertain.
“I brought your book back,” I said, the mundane words feeling absurd.
“Thank you.” Her gaze flicked to the tome on the desk. The dog-eared page. She knew what was marked there.
Mary wiped the gel from her hands. “Well, my work here is done. Data collected, observations logged.” She gave us both a smile that was finally, unmistakably, edged with a little hurt. “See you around, Vy.”
She left, the door sighing shut behind her, leaving us in the charged silence.
Scarlett walked slowly to the main console and closed the brain model with a definitive click. The screen went dark, reflecting our fractured silhouettes back at us.
“She had no right,” Scarlett said, but the anger was directed inward.
“Is it true?” I asked, standing. “What the data showed?”
She didn’t pretend to misunderstand. “It’s a representation of blood flow and electrical activity. It’s true as data.”
“That’s not what I’m asking.”
She turned to face me, leaning back against the console as if for support. Her composure was reassembling, brick by brick, but the fracture was still visible. “Yes,” she said. The word was simple, heavy. “When I see you, or think about you, my brain doesn’t… wander. It focuses. Completely. It problem-solves you. It’s… efficient. And alarming.”
“Alarming?”
“Because it’s not just attraction. It’s an assessment. A continuous, involuntary assessment of value, risk, and potential.” She ran a hand through her hair. “Mary thinks
She ran a hand through her hair. “Mary thinks it’s just fascinating data.” Scarlett’s voice was low, strained. “But it feels like a violation. She mapped my subconscious.”
She looked directly at me, and a fresh, deep blush spread across her cheekbones, vivid under the lab’s sterile lights. It was a second wave, hotter than the first, betraying a shame that her composed explanation couldn’t mask.
The air smelled of stale coffee and the sharp, clean scent of the electrode gel still cooling on my skin. I stood up from the chair, the wires now disconnected, feeling unsteady.
“So I’m a stimuli set.” I said it flatly, testing the words. “A controlled variable that breaks your calibration.”
“No.” She took a step forward, then stopped herself. “You’re the uncontrolled variable. The one that reroutes the whole experiment.” Her hands flexed at her sides, restless. “Before, my mind was a clean room. Now, it’s… littered with projections. Cost-benefit analyses of your smile.”
I barked a short, surprised laugh. It echoed off the tile. “That’s the least romantic thing I’ve ever heard.”
“I know.” That admission seemed to cost her. She glanced at the darkened monitor. “Katy would have written a sonnet. I built a scatter plot. It’s who I am.”
The hum of a server fan filled the silence. I moved closer, until only the console separated us. I could see the pulse in her throat, quick and visible.
“Show me,” I said.
Her eyes narrowed. “What?”
“The raw data. The untitled spreadsheet. ‘The Cost of Hesitation.’” I recalled the screen from when I first walked in. “If we’re being scientific, let’s be thorough. No more interpretations from Mary.”
Scarlett hesitated for only a second. Then she turned, her fingers flying over the keyboard with practiced ease. The screen lit up, not with brain scans, but with columns and rows. It was a timeline, stretching back weeks.
I recognized the dates. The rooftop. The dinner after. Our Poli Sci lectures.
Next to each date were numerical entries, ratings on a scale. Cognitive load. Emotional valence. Predictive certainty. The numbers from before our first dinner were low, flat. Then, a spike. Then, a steady, climbing trend.
The last entry was from today. Predictive certainty still showed a question mark.
“See?” she whispered. “I can model the market reaction to a policy shift. I can’t model this. Not yet.”
“The question mark is honest,” I said. My own heart was doing something my statistics minor couldn’t quantify.
“It’s the only honest part.” She closed the file. “The rest is just me trying to force a pattern onto something that, by definition, resists patterning.” She finally looked at me again, her blush faded but her expression laid bare. “I don’t know how to do this without the framework.”
I reached across the console and took her hand. Her skin was cool, her fingers tense for a moment before they intertwined with mine. It was a simple, deliberate action.
“Then don’t use one,” I said. “Just be here. In the lab. With the messy data.”
She let out a breath I didn’t know she was holding. Her thumb moved, a slow stroke across my knuckle. “That’s terrifying.”
“Good,” I said, echoing her word from the restaurant. “It means it’s real.”
From the doorway, a cleared throat made us jerk apart. Mary stood there, a forgotten notebook in her hand. Her smirk was gone, replaced by something softer, almost apologetic.
“Sorry,” she said. “Left this. But, uh.” She looked between us, at our hands now separated but still hovering close. “The lab is booked for a sleep study in ten. You’ll need to clear out.”
Scarlett nodded, already shutting down systems. “We’re leaving.”
Mary lingered for a second. “Katy’s at the pub. She’s asking for you, Scar.” The message hung there, a splinter of the old world wedging into the new.
Scarlett didn’t look up from the keyboard. “I know.”
Then Mary was gone. The silence she left behind was different, charged with a new decision. Scarlett straightened, slinging her bag over her shoulder. She looked at me, all traces of the blush gone, replaced by a resolved clarity.
“I’m not going to the pub,” she said. It wasn’t a declaration for me. It was one for herself.
“Where are you going?” I asked, matching her tone.
“Anywhere else.” She picked up the psychology textbook I’d returned, her fingers brushing the dog-eared page. “Walk with me?”
I took my coat. “Yeah.”
We turned off the lights and stepped into the hall. The door clicked shut behind us, locking away the glowing screens and the maps of her mind. The corridor was empty, lit by intermittent fluorescent panels that buzzed overhead.
We walked without touching, but the space between us felt solid, chosen. The momentum was quiet, but it was there, carrying us forward into the unknown night.
The momentum was quiet, but it was there, carrying us forward into the unknown night. The hallways of the science center were a maze of polished linoleum and echo, our footsteps the only sound. We didn’t speak until we pushed through the heavy exterior doors into the bite of the autumn air.
“She shouldn’t have done that,” Scarlett said finally, her words forming a cloud in the chill. She meant Mary, and the brain scans, and the brutal exposure of her private data.
“But it was true.” I shoved my hands deep into my pockets, the cold seeping through my coat. “That’s what makes it worse, right? It wasn’t a lie. It was a violation of a truth.”
She made a low sound of agreement, a frustrated exhale. We walked across the quad, a vast darkness punctuated by islands of jaundiced light from the old iron lampposts. “I feel dissected. And I handed her the scalpel by running those scans in the first place.”
“Why did you?” I asked. The question had been burning since I saw my name on the screen.
She was silent for so long I thought she wouldn’t answer. “I needed to understand what was happening to my own focus,” she said, her voice barely above a whisper. “It was a deviation from baseline. I was troubleshooting.”
“And what was your diagnosis?”
“System overload.” She stopped walking, turning to face me under one of the lamps. The light caught the edges of her hair, framing her face in gold. “The architecture holds, Vy. But the occupancy is… unpredictable. It defies my initial models.”
A wind swept through, pulling at our clothes, carrying the dry rustle of fallen leaves. It was the same wind from the rooftop, but it felt different now. Cleaner.
“Katy’s at the pub,” I stated, watching her.
“I know.”
“You should go.”
Her eyes searched mine. “Is that what you want?”
“No.” The answer was immediate, unadorned. “But I need to know you’re not here just because she’s a variable you’ve controlled for. That you’re not just proving a point to her, or to yourself.”
She flinched, and I knew the strike had landed. It was the same cold calculus she’d applied to our beginning. I was turning her own methodology back on her, and it was brutal.
“Every action has a counter-action,” she said slowly, her words measured. “Choosing you creates a force against my history with her. That force is real. It has weight. But it is not the cause of the initial choice. It’s a consequence.” She took a step closer. “The cause was the deviation. You. The cause is that my prefrontal cortex, for reasons I am still trying to fully comprehend, categorizes you as the most critical problem to solve. The most fascinating dataset.”
“I don’t want to be a problem, Scarlett.”
“You’re not.” She reached out, her fingers brushing a strand of wind-blown hair from my cheek. The touch was electric in the cold. “You’re the solution I hadn’t programmed for. You’re the outlier that makes the old model obsolete.”
Her hand stayed there, cupping the side of my face, her thumb resting on my cheekbone. The night seemed to contract around that single point of contact. All the spreadsheets, the brain scans, the hesitant looks across lecture halls—they collapsed into this.
Her other hand came up, mirroring the first, framing my face. Her gaze dropped to my lips, then back to my eyes, a question written in the dark pools of her pupils. There was no algorithm for this, no predictive certainty. There was only the shared breath clouding between us, the distant sound of a car on the street beyond campus, and the terrifying, thrilling silence of a hypothesis about to be tested.
I closed the distance.
It was not like the rooftop. That had been a shock, a sudden channel cut through a logjam. This was a convergence. Her lips were soft, cool at first, then warming rapidly against mine. The kiss was deliberate, a slow, deep verification. I felt her breath catch, then release into me as her fingers slid back into my hair, anchoring me to the spot.
She tasted of winter air and the faint, distant sweetness of the tea she must have drunk in the lab. My hands found the wool of her coat, gripping tight, pulling her closer until the space between us vanished. The analytical firestorm she’d shown me on the screen, that spectacular cognitive engagement, was here now, translated into pure, unmediated physical focus. Every ounce of her attention was on this, on the feel of my mouth on hers, the subtle shift of balance, the shared warmth.
It was a kiss that contained the entire argument we’d been having since we met. It was an answer and a question, a conclusion and a new experiment begun.
We broke apart, breaths mingling in short, visible clouds. Our foreheads stayed touching. Her eyes were closed. “Well,” she whispered, the word a vibration against my skin. “The data is conclusive.”
“The data is conclusive.”
Her words hung in the cold air between our mouths, a scientist’s poetry. I felt her smile against my lips, a brief, real fracture in her composure. We stayed there, foreheads touching, breathing the same charged space, for one more second.
Then her phone screamed.
It was a violent, jagged sound in the quiet quad. A custom ringtone—a pulsating, aggressive synth beat she’d never use. It was Katy’s. She’d told me once, laughing, how she’d programmed it as a joke. So I always know it’s an emergency, she’d said. Her emergencies.
Scarlett jerked back as if scalded. Her hands fell from my face.
The phone buzzed and shrieked in her coat pocket, a trapped animal. The screen’s glow bled through the wool, casting a frantic blue light on the frozen grass near our feet. She stared at it, her expression shifting from dazed intimacy to cold recognition in a heartbeat.
“Don’t,” I said. The word was out before I could think.
She looked at me, conflict warping her features. The lab’s exposed blush was back, but now it was splotchy, stressed. “It’s that ringtone. She only uses it when—”
“I know what it means.” My voice was flat. The warmth from the kiss was leaching away, replaced by the familiar, metallic taste of being second. “So answer it.”
“Vy—”
“Answer it, Scarlett. Or this,” I gestured at the space where we’d just been connected, “is just another controlled experiment. One where you ignore the inconvenient variable.”
The phone stopped. The silence it left was worse.
For three breaths, there was only the wind. Then it started again, the synth beat more insistent, a digital siren.
Scarlett closed her eyes, a muscle ticking in her jaw. She pulled the phone out. The screen lit up her face from below, giving her features a ghoulish cast. KATY CALLS SCARLETT. flashed once, twice.
She swiped to answer and brought it to her ear. “Katy.”
I couldn’t hear the words, only the sound. A jagged, wet torrent of noise spilled from the receiver, tinny and desperate. Crying. No, not just crying. Hysterical, gulping sobs interspersed with choked, slurred words.
Scarlett’s posture changed entirely. She turned slightly away from me, her shoulders curving inward. “Where are you?” Her voice was low, clinical. The voice you use on a ledge. “Say it again. Say the address.”
More broken glass sounds from the phone. A loud clatter, like something falling.
“Okay. Just stay there. Don’t move. Don’t do anything.” She spoke with forced calm. “I’m coming. Right now.” She hung up and stood for a moment, the phone clenched in her white-knuckled hand. When she turned to me, the woman who had kissed me was gone. In her place was a crisis manager.
“She’s at a house party in Somerville. She’s alone, she’s drunk beyond coherence, and she’s not safe.” Scarlett’s words were rapid, logistical. “I have to go.”
“Of course you do.” I heard the icy detachment in my own voice. It was a shield.
“This isn’t about choosing her.” She took a step toward me, but I took one back. The distance was physical, immediate. “This is about basic human responsibility. She’s my friend, and she’s in trouble.”
“She’s your heart’s chaos generator.” The old anger, the one from the rooftop, was back, cold and crystalline. “And you’re her reliable one. Her emergency contact. Nothing has changed.”
“Everything has changed!” The shout was raw, startling us both. She sucked in a sharp breath, lowering her voice. “What do you want me to do? Hang up? Let her wander into traffic because I’m finally happy? Is that the clean architecture you want?”
It was a fair shot. It landed. We stared at each other, two strategists across a battlefield of someone else’s making.
“Go,” I said finally, my energy bleeding out. “Be a hero.”
She flinched. “Come with me.”
The offer was so unexpected I laughed, a short, harsh sound. “Are you insane?”
“Probably.” She ran a hand through her hair, the gesture frantic. “But you’re part of this equation now. The new variable. I’m not going to hide you, or hide this, from the mess of my past. If we’re building something real, it has to exist in the real world. And the real world has drunk, crying Katy in it.”
The logic was perverse. It was also, I realized, perfectly Scarlett. She wasn’t asking me to prove I trusted her. She was asking me to witness the complexity she came with. To include the outlier data.
The wind bit through my coat. Somewhere, a block away, Katy was shattered and alone, and she had called the one person she knew would always come. That fact was a stone in my stomach.
“If I come,” I said slowly, “it’s as your girlfriend. Not as a spectator. Not as a ghost. You introduce me as that. You hold my hand. You choose, publicly, in front of her, which side of the door you’re on.”
I saw the calculations flash behind her eyes. The risk assessment. The potential for catastrophic emotional fallout. She weighed it all in the space of two seconds.
“Deal.” She held out her hand, not for a romantic touch, but a pact. “Get in the Uber with me. Please.”
I looked at her outstretched palm. I thought of the brain scan, the magnificent, focused firestorm. I thought of the kiss under the lamppost, a moment already being swallowed by this new emergency.
I took her hand. It was cold. “This is a terrible idea.”
“I know.” She was already pulling me toward the street, her phone out to summon a ride. “But it’s the only one that doesn’t require pretending you don’t exist.” The car was two minutes away. We waited in silence, our breath clouding together again, but the intimacy was gone, replaced by a grim, shared mission.
The Uber arrived. We slid into the backseat, the fake-leather smell of artificial cherry enveloping us. She gave the address—a street I didn’t know.
As the car pulled away from the curb, she reached over in the dark. Her fingers found mine and laced through them, tight. It wasn’t tenderness. It was an anchor point.
She stared out the window at the passing streetlights, her profile etched in tension. “Thank you,” she whispered, so low the driver couldn’t hear.
I didn’t answer. I just watched the familiar campus shrink behind us, feeling us accelerate toward the epicenter of the old world’s fault line, my hand locked in hers.