I Hired My Best Friend's Sister, But What She Did To Me At A Pool Party Changed Everything

Mark rang while I was red-penning a misaligned elevation.
“Do me a solid, mate—interview Clara. She’s between things and she’s, well, brilliant.”

I grunted, because “brilliant” from Mark usually meant can spell her own name. But he had once pulled me out of a Galway bog at 3 a.m.; debts like that don’t expire.

She arrived Tuesday at ten-thirty, twenty-three minutes early. I was still locking the bike and caught her unfiltered: white shirt tucked into denim, hair yanked back like an afterthought, eyes the flat grey of cast concrete—nothing like Mark’s sloppy cheer. She extended her hand before I managed to wipe the graphite from mine.

“Clara Gallagher. Thank you for the time.”

Her grip was dry, deliberate. I felt inspected, not greeted.

Inside, the office was one converted Georgian room smelling of laser-printer toner and last night’s curry. I slid her CV across the desk: half a page, two summer internships, no degree finished.

She didn’t apologise for it. “University slowed me down,” she said. “Buildings don’t live in lecture halls.”

I asked why ceiling heights in social housing mattered. She answered with a calculation of air volume per occupant and the psychological radius of personal space, citing a Dutch study I’d skimmed and forgotten. While she spoke she rotated the model on my screen without permission, isolating the kitchen wing and mirroring it so the morning light fell three minutes earlier into the courtyard. The fix was elegant, obvious only after you saw it. My pulse gave an irritating hop.

I should have ended it there—thanked her, filed the form, told Mark she wasn’t the right fit. Instead I heard myself outlining the probationary salary, the coffee-making rota, the fact we worked Saturdays when clients panicked. Each clause was a test; she absorbed them like specifications.

When I stood, she did too, an inch closer than standard. A faint chlorine smell clung to her skin, as if she’d swum here. The distance was thin enough for me to notice the small triangle of sweat darkening her collar and then to notice myself noticing.

“I can start Monday,” she said.

I told her I’d be in touch, my voice suddenly formal, the way it got in school before a fight. She smiled—not grateful, not flirtatious, but certain—and walked out, sneakers silent on the stripped pine.

The door clicked. The office felt rearranged, though nothing had moved except the cursor still blinking inside her mirrored kitchen. I sat, pressed my thumbs against the desk edge until the skin whitened, and understood, with perfect clarity, that I had just opened a door I would spend the next months trying to close.

Monday morning she arrived with a canvas tote full of colour-coded folders and a steel travel mug that clinked against the door handle. Before I finished hanging my jacket she was already kneeling beside the plan chest, sliding drawers open, lifting tracing paper by the corners as though the sheets were contagious.

“Your filing is alphabetical by project name,” she called without turning. “That breaks the minute a client re-brands.”

I told her to leave it. She didn’t. By coffee time the timber library was rearranged by density, oak on the left, balsa on the right, each block labelled in her small block capitals. My system—chronological by supplier, the one I’d used since buying the practice—sat in a recycling box leaking glue samples.

I summoned her in at four, closed the door, kept my hands flat on the desk so they wouldn’t curl into fists.

“Clara, you were hired to assist, not redecorate. Put everything back.”

She stood, arms loose at her sides, chin lifted just enough to bare the tender skin under her jaw. A pulse beat there, steady.

“Efficiency isn’t decoration,” she said. “You lose ten minutes a day hunting for the correct plywood. That’s forty hours a year—an entire week of labour you bill at two hundred euro an hour.”

The calculation was accurate; I hated her for it. My voice stayed low.

“This office runs on precedents. I need to know where things were in 2019 without thinking.”

“Then you’ll never know where they could be in 2024.”

Silence stretched, thick as the plaster samples she’d stacked. I felt the heat rise up my neck, the same heat that preceded shouting, or something worse. She didn’t blink. For an instant the room narrowed to the space between her mouth and mine, the possibility of shutting her up with either cruelty or contact. I chose the former.

“Fix it tonight or don’t come back tomorrow.”

She nodded once, not submission—acceptance of terms. When she turned, her shoulder brushed the hanging lamp, setting the bulb swinging so that shadows slid across the walls like blueprints being rolled and unrolled. The door shut quietly; the click sounded like a timer starting.

The building fell quiet at seven-thirty when the letting agent next door slammed their communal front door. After that the only sounds were the radiator ticking and, every few minutes, the fridge in the kitchenette coughing into life. I kept my head over the Henderson drawings, red-lining the stair core that refused to fit within the seventeen-metre footprint. Nothing worked: the treads either ate the corridor width or left a residual triangle too small for a cupboard. I had sketched six iterations and hated all of them.

Across the room Clara’s mouse clicked, a soft metronome. She had said nothing since six, when I told her she could leave if she wanted. She had only shrugged and opened a new file. Now her screen glowed blue on her face, highlighting the faint shine of concentration above her eyebrows. I tried not to look.

At ten-fifteen I dropped my pen. The plastic rolled, stopped against the metal rim of the lamp. I kneaded the bridge of my nose, feeling the ache spread down into my shoulders. The drawing swam. I was deciding whether to admit defeat when she stood, bare feet silent on the boards, and placed a single sheet on my desk.

“Rotate the core ninety degrees,” she said. No preamble, no apology for speaking after hours. “Split the landing, put the storage under the half-flight. You gain two hundred millimetres and the corridor breathes.”

I stared. The solution was drawn in clean graphite: one straight flight, a quarter-turn, a niche for coats. The dimensions were correct, the headroom compliant. I had been trying to solve the wrong problem for three hours; she had changed the question and answered it in four lines.

“It’s live-load bearing,” I muttered, testing the excuse.

“Two hundred mil steel plate in the party wall. Already checked the structural regs.” She tapped the margin where she had pencilled the load path. Her nail was bitten, ink smudged on the cuticle.

I picked up my pen, added the plate, felt the drawing settle into place like a bolt sliding home. The stair fitted. The corridor widened. The residual triangle became a seat with a window. I could see the client signing off, the contractor relieved. I should have felt triumph; instead I felt the slow thud of something shifting inside my chest.

“Good,” I said, the word insufficient. I meant thank you, meant sorry, meant how did you see that when I couldn’t. None of it arrived.

She leaned one hip against the desk, arms folded, watching me finish the note. Her shirt had pulled free on one side, revealing a strip of skin and the waistband of her skirt. A freckle sat just above the elastic, small, round, impossible to ignore. The radiator clanked and we both stayed still, as if movement might break the new, fragile filament stretched between us.

I capped the pen. The drawing was done. The office smelled of toner and the orange she had eaten earlier. I became aware of my own breathing, of hers. She didn’t step back.

“Thursday deadline met,” she said, voice lower than during the day, almost conversational. “We could invoice the variation.”

“We could,” I answered, and heard the husk in my throat. I looked at her mouth, then made myself look at the wall behind. The lamp buzzed. Somewhere below, a car door slammed.

She straightened, gathered her mug, her notes. “I’ll save the file,” she offered, already turning. The moment thinned, ready to snap. I nodded, not trusting my voice, and listened to her walk away, the soft click of the mouse starting up again like a second heartbeat in the room.