She Slapped England’s Most Feared Duke… Then He Refused to Let Her Go

Chapter 7

She was late by two minutes, and the Duke noticed.

“You are late,” he said without looking up from the desk, which was covered tonight with papers, letters, codes, maps — the detritus of half an empire, spread across the mahogany like a hand of cards.

“By two minutes.”

“That is still late.”

Isabelle removed her gloves, folding them with care. “Your clock runs fast.”

At that, he glanced up. The faintest hint of amusement flickered in his eyes — and there it was again, that current she could not name, alive between them across the width of the room. You are different, that look said. Everything about you is different.

“Confident as ever,” he said.

“Accurate as ever, your grace. There is a difference.”

“There is.” He slid a sealed envelope across the desk toward her. “This arrived from Lisbon yesterday.”

Isabelle opened it carefully. Her eyes moved quickly across the strange symbols, and a small, quiet part of her that had not spoken in years — the part that loved puzzles for their own sake — began to hum.

“Visionaire cipher,” she murmured.

The Duke watched her closely. “You recognized it immediately.”

“It’s a common diplomatic method.” She paused, frowning. “But the key is unusual.”

“How so?”

“The rotation changes every seven characters.” She unfolded it flat, smoothing the creases with her palm. “That’s not standard practice. It means whoever wrote this expects the reader to know the sequence before they begin. It’s a message designed for one specific recipient.”

“Interesting.”

She reached for the pen. “Give me ten minutes.”

The room fell silent again. Firelight flickered across the walls. The only sound was the quiet scratch of ink — that sound, which she had known all her life, the sound of a mind working against paper. The Duke watched her work, and she felt his gaze on her like the warmth of a wall in winter sunlight.

Most women in London were trained for politeness. For charm. For graceful, decorative silence.

Isabelle Fairmont possessed none of those qualities.

She frowned while thinking — the whole world could have ended beyond that door and she would have kept frowning at the page, one shoe tucked under her thigh, a strand of hair escaping its pin. She tapped the pen against her lower lip. She muttered calculations under her breath, numbers and letters woven together in a low, urgent whisper.

She behaved like a mathematician, not a lady.

It was — the Duke realized, watching her from across the desk — unexpectedly fascinating. He had spent his life surrounded by decorum, by women who had been drilled to perfection like parade horses. No one had ever frowned at his cyphers with their whole body. No one had ever called him accurate-as-ever. No one had ever slapped him, come to his library, picked up his pen without permission, and solved in a quarter of an hour what had stumped the best codebreakers in the Crown’s employ for a week.

After several minutes, she stopped writing.

“Done.”

The Duke stepped closer. “What does it say?”

“Portuguese fleet movements.” Her voice was flat, professional, but her eyes were dark. “They’re coordinating with French vessels near Cadiz. Arrival windows, rendezvous points, resupply schedules. This is not a merchant cipher, your grace. This is a plan of attack.”

“That shouldn’t be possible.”

“It is — if someone inside the British trade network is leaking the schedules.” She looked up at him. “Someone with access to the Admiralty’s shipping lists. Someone who knows exactly when our ships are where.”

The Duke’s gaze darkened. “Someone powerful.”

“Yes.”

Silence stretched between them, heavy with implication.

“Miss Fairmont,” he said quietly. “You realize what this means.”

“I assumed already, your grace. I am now involved in matters of state.”

“You could be questioned.”

“I expected that.”

“You could become a target.”

At that, she finally looked up — a long, steady look, without fear and without bravado. “Your grace. I have already been ruined by society once. I have very little left to lose.”

Something in that answer shifted the atmosphere of the room. The fire seemed to settle. The rain seemed to quiet. The Duke studied her, and the silence between them grew dense and warm, like bread in an oven.

“You are either very brave,” he said, stepping closer, “or dangerously stubborn.”

“Both, your grace. Usually at the same time.”

His mouth almost smiled. “I am learning that.”

Hours later, the final code was complete.

Isabelle stretched, rubbing her fingers — they were stained with ink, and there was a shadow of exhaustion under her eyes, and she had never been more alive. “There. All of it. Every message, decoded and annotated.”

“You work like a soldier,” the Duke observed. He had shed his waistcoat somewhere in the course of the night; his sleeves were rolled to the forearm, and he looked, for the first time since she had known him, like a man rather than a monument.

“Patterns do not wait politely for one to put on one’s best gown, your grace.”

“You’ve done this before.”

“Yes.” She nodded, and something in her voice softened. “With my father. He taught me mathematics when I was twelve. He used to say — numbers are the only honest language left in the world. Anyone can lie with words. But the pattern never lies.”

“And espionage?”

“No.” She met his gaze. “Only truth.”

The Duke looked at the translated papers again, then slowly back at her. “You still believe the documents condemning your father were forged.”

“I know they were.”

“And if we discover otherwise?” His voice was careful, almost gentle. “If we reopen the case and find that Thomas Fairmont —”

“Then I will accept the truth.” Her voice did not waver. “I told you before, your grace. My loyalty is to patterns. I would not dishonor my father by denying what the evidence shows, whatever it shows.”

The Duke walked slowly toward the window. Rain streaked the glass outside, turning the lights of London into smeared gold.

“You understand,” he said quietly, “that exposing the wrong man could destroy powerful families. Families that have served this country for generations.”

“Justice often does.”

He turned back. “And if that family were mine?”

The question hung in the air — heavy, dangerous, alive.

Isabelle’s breath caught. “Is there reason to suspect that?”

The Duke did not answer immediately. Instead, he studied her face — the ink-stained fingers, the stubborn chin, the weariness she was too proud to hide — as though he were mapping it.

“I am asking,” he said softly, “whether your loyalty to the truth is greater than your fear of me.”

“My loyalty to the truth,” she said, “is greater than my fear of anyone.”

Another long silence followed.

And then something unexpected happened. The Duke laughed — not the polite aristocratic chuckle used in drawing rooms, a sound like a glass being tapped. A real laugh. Low, quiet, almost surprised, as though he had discovered something in himself he had forgotten existed.

“God help the man who tries to lie to you, Miss Fairmont.”

“Many already have.”

“Yes.” He looked at her carefully, and something in his gaze had changed — deepened, warmed, grown more dangerous. “I suspect that is about to change.”

Their eyes held too long. The fire crackled softly behind them. Neither moved. Neither spoke.

Until a sudden knock struck the library door.

Both turned. The Duke’s expression hardened instantly — the warmth and the openness and the almost-smile vanished like a candle blown out, and the monument returned.

“Enter.”

The door opened. Lady Harrington stepped inside.

Her sharp eyes moved from her brother to Isabelle, then to the scattered code sheets across the desk. For a long moment she said nothing. Then her voice cut through the room like ice.

“William.”

The Duke straightened. “Charlotte has been born and I have been a widow—” He stopped, corrected himself. “Yes.”

“You are working with my governess.”

It was not a question. His answer was calm. “Yes.”

Lady Harrington’s gaze moved slowly to Isabelle, and there was something in it that frightened her more than the Duke ever had — the cold, complete assurance of a woman who had spent her life making problems disappear.

“You may leave us, Miss Fairmont.”

Before Isabelle could move, the Duke spoke.

“No.”

The word echoed through the library like a dropped hammer.

Lady Harrington stared at him. “William.”

“The matter, Charlotte, is not yours to dispose of.” The Duke’s voice had gone dangerously soft. “Miss Fairmont is in my service. Her movements are my concern, not yours. And she will not be sent from a room like a dismissed maid while she is conducting the Crown’s business.”

“Conducting business,” Lady Harrington repeated. “At midnight. Alone. In your library.”

“Yes.”

“Is that wise?”

The Duke smiled — a thin, cold smile with no warmth in it. “Wise, Charlotte, would have been listening to Miss Fairmont’s mathematics before her father died of shame in a rented room in Bloomsbury.”

Lady Harrington recoiled as though he had struck her.

And Isabelle — standing frozen at the desk, ink on her fingers, heart hammering — understood in that instant that something had changed. The Duke had chosen a side. Her side.

And everyone in London would pay for it.