Chapter 3 Pressure Differential （Wren）
PRESSURE DIFFERENTIAL (WREN)
The lecture hall is quieter than anywhere else on campus at this hour. Calculus settles into order on the board, and my nervous system can finally work with this.
Theo’s in my class this semester.
He’s two seats down and one row forward, profile in three-quarter view. Elbow on the desk, pen tapping in even beats that sound soft slate blue. His glasses have slipped down his nose again. He hasn’t noticed. He never does.
He’s broad through the shoulders under a Henley. His forearm is roped and steady where it brackets the notebook. Fine-line ink traces neat constellations along the skin—sharp black stars, precise connecting lines.
It should just be art on skin. I tell myself it is.
When he leans in to think, really think, his back sets, solid and sure. The sight leaves a faint ache under my ribs. It makes me want to be seen. Not touched. Just seen. Just once.
“Before we move on—particular solutions.” Professor Feldman taps the equation he left hanging. “Who wants to take a stab at it?”
The room performs mass stillness.
I raise my hand because letting the silence drag makes my ribs ache.
“Miss Marin.” Feldman looks relieved. “Show them the method.”
I stand, ignoring the whispers that trail me—teacher’s pet, try-hard—and head to the board. The marker is cool in my hand. “For a cosine input, we assume a cosine response. Match constants, simplify.” The math falls into place, neat and contained. I cap the marker and step back.
“Correct,” Feldman says. “Textbook.”
I head for my seat.
The door at the top of the lecture hall swings open.
Cold air floods in first. Then Kieran O’Connor walks through it.
The room shifts. Sound tilts warmer, louder, like someone just turned up the volume without asking. A girl in the back row lets out a muffled giggle. Someone whispers, “Oh my God, that’s him.”
Professor Feldman pauses mid-sentence.
Kieran doesn’t apologize for being late. He enters the room and claims it, doing a casual scan of the rows.
Then he spots me.
And heads straight down the aisle.
He stops at the seat beside mine, the one that stays empty because nobody sits next to the nerdy girl who volunteers.
“Mind if I?”
His tone is casual, but he waits, a hand braced on the desk. I nod, and he drops into the chair. His knee angles close to mine. Not touching, but close enough that I’m aware of every inch between us. Close enough that I have to remind myself I don’t want him there.
He smells faintly of cold air and soap and something else I shouldn’t be cataloging. His hair is still damp. There’s a fresh cut on his lower lip, and I’m annoyed that I noticed.
Around us, the room crackles. A girl two rows back leans so far forward she’s practically falling over her desk. The sudden spotlight that comes with being chosen by the guy everyone watches feels unsettling. Heat crawls up my neck while my stomach locks down.
Feldman clears his throat. “Thank you, Ms. Marin. Everyone, copy that down.”
Kieran leans in just enough that I feel the heat off his shoulder. “Should I be taking notes?”
His voice lands in steel blue—steady on the surface. Underneath, silver threads catch, bright with white-gold.
I don’t look at him. “If you plan to pass.”
He smiles, but his pen stays capped.
Feldman launches into applications. My pencil moves on autopilot.
Beside me, Kieran doesn’t write. He just watches, posture loose, his eyes tracking the equations like he’s memorizing the shape of them.
The room keeps half turning toward us. I can hear the conclusions forming: Hockey royalty. Engineering 204. Sitting next to her.
I keep my eyes on the board. The numbers behave. My body doesn’t.
Theo raises his hand. “Could you go over the forcing term again?” His voice lands soft sage-green, calm and familiar. My shoulders ease a fraction.
While Feldman explains, I feel Kieran’s attention on me. Not invasive exactly, more analytical. As if he’s studying vectors, not skin. Watching how I move the pencil, how my wrist keeps time with equations.
It should bother me. It doesn’t.
And that’s a problem.
Then Professor Feldman says the words students love and hate: “Work together.”
Chairs scrape. Voices rise. Kieran doesn’t move toward anyone else. Doesn’t move away from me.
I keep my eyes on my notes. “You’re actually in this class? Aren’t you a senior?”
“Switched to MechE,” he says. “Playing catch-up.”
That lands wrong. He says it like it’s nothing. Like this isn’t the class I built my weeks around, the one I fought to place into early.
I keep my voice even. “Good luck.”
Theo appears at our desk with his notebook and that easy smile that makes my pulse kick.
“Hey. Want to team up?”
He has his sleeves shoved up again, forearm flexed around the spiral binding. I keep my eyes on the notebook. I don’t always succeed.
“Sure,” I say, a little too eagerly.
Kieran’s long legs are stretched under the table, hockey-star appeal dialed to eleven. I am suddenly sitting between the two most desirable guys on campus—one who knows it and isn’t beyond working it to his advantage, and one who has no clue.
The pressure differential is immediate. I keep my eyes on the page.
Kieran leans in, elbows on the desk. “Mind if I join you guys? Could use the help.”
If Theo were interested in me at all, there would be some reaction. A pause. A shift. Anything. Instead, he pulls over a chair without hesitation, completely unbothered. “Yeah, of course.”
Equal-opportunity friendly.
He sets his notebook down and starts outlining the problem, calm and focused, as if we’re three random classmates who happened to be in the same orbit.
It lands quietly. Heavy anyway.
I tell myself that’s fine. Good, even. Less mess. Less noise.
We move through the equations. Theo talks through his approach, voice smooth and familiar, and I add clarifications. He nods, scribbles, keeps his forearm braced on the desk where the ink keeps dragging my attention away from the numbers.
And Kieran… Kieran actually contributes. Not guesses. Not charm. Real insight. His ideas are sharp, filling the empty spaces in the group.
I focus harder on the work. On the math. On keeping my face neutral while I sit between the campus golden boy and the oblivious crush I am clearly going to have to outgrow.
When Theo stalls, Kieran says quietly, “Isolate the steady-state part with the cosine term first.”
Theo blinks. “Oh. Right.” He glances at me like I might have fed Kieran the line. I didn’t.
Feldman circles the room and stops at our table. He clocks Kieran and clears his throat. “Welcome to 204, Mr. O’Connor. Hang onto these two—they know what they’re doing.”
I don’t like how much weight that carries.
My notes end up cleaner than they need to be. When I’m done, I slide the page slightly toward the middle. Not toward him. Just not entirely mine anymore.
Kieran leans in to look. He doesn’t make a joke or try to charm his way through it. He studies the work for a long moment, and something in my chest misfires.
The clock ticks its bright yellow beat. Class ends.
Chairs screech back. Backpacks zip. The room explodes.
Feldman raises his hand. “Before you go, keep the groups you worked in today. Semester project partners. Office hours are posted.”
Wait. What now?
“Partners?” Kieran says quietly, glancing toward Theo.
I’m already packing. Pencil away. Notebook closed. My hand is steady. My breathing isn’t.
Before I can answer, a girl from the back row slides into the aisle ahead of him, smiling too brightly. “Hey. Can I grab your number for notes?”
Kieran’s jaw tightens a fraction. His gaze flicks to me, then back to her—caught, recalibrating. The moment stretches, awkward and public, before his polite reflex kicks in.
I shoulder my bag and step into the flow of bodies, leaving him without hearing an answer.
Theo is already halfway down the hall, tugging the zipper of his jacket up as he laughs at something the girl from his lab section says. The fabric pulls tight across his arm, the clean line of muscle unmistakable even through layers.
His hair falls into his eyes. He pushes it back without thinking and keeps walking.
Two girls by the water fountain go silent as he passes. One straightens her posture. The other gives a hopeful little nudge.
Aubrey falls into step with me, heading out from her World Literature class. “How does a guy that smart have time to look like that? Does he sleep?”
I try not to sound wistful. “He’s on the swim team.”
Aubrey blinks. “Oh. Yeah. That explains…all of that.” She exhales, low. “God, he really does have that whole hot-genius thing going, doesn’t he?”
My ears warm. “Yep. He does.”
My phone buzzes, forcing me to look away.
UNKNOWN:
Partners should probably exchange contact info
Stats tutoring flyer on the bulletin board had your number
Hope that’s not weird —K
I stare at the screen. At that casual K, like we’re already familiar. Like sitting next to me once earned him the right.
“He got your number,” Aubrey breathes, reading over my shoulder. “That’s—”
“From my tutoring flyer,” I say quickly. “It’s public information.”
“He found your number. On purpose.” She’s delighted. “Giiirl.”
“It’s nothing.”
“It’s something.”
I shove my phone in my pocket, but the message sits there, blue and steady and impossible to ignore.
Just like him.