A Spy Inside The Castle by M. B. Courtenay (EXCERPT)

We have a terrific excerpt for you today, dear readers, from a debut novelist who isn’t afraid to explore the bleeding edge of espionage!

Long-time readers will know that I’m a sucker for a mythological retelling, especially in a new and unexpected genre. M B Courtenay’s A Spy Inside The Castle riffs off the myth of the Minotaur in its Labyrinth, to present a compelling drama of politics and spycraft as a reluctant analyst is thrust into the cutthroat world of operations.

Ethan Briar’s ability to analyze and predict risks definitely does not mean that he’s happy to actually take them himself. But after receiving a cryptic message warning of a hidden war, he finds himself pulled into the shadowy halls of Castlemartin Manor, a decaying stronghold with the quantum supercomputer ARCLIGHT at its heart. Built to predict the future, ARCLIGHT has since been used to manipulate global events. Ethan’s task is to unmask a mole whose betrayal could take down the US government… or worse.

Read on for a perhaps surprisingly sexy excerpt, as Ethan gets ready to be introduced to ARCLIGHT:

~~~~~~~

ARCLIGHT

GOTHIC SALON
CASTLEMARTIN
SEPTEMBER 29, 2022, 2331 BST
(PRESENT DAY)

The gothic salon where Ethan was to meet Diana exuded the kind of old-world luxury that invited silence. Soft leather chairs framed a polished oak table, the centerpiece a glass globe lamp. Heavy drapes muted the sounds of another lingering storm beyond the castle’s stone walls. Diana settled into the chair, her eyes heavy-lidded, fixed on the mirror before her. It was an odd, almost haunted stare, as though she was searching for someone else within the contours of her own face.

Her mind was a lattice of brilliance, an intricate network connecting seemingly disparate threads into cohesive narratives. If she had been a painter, she’d have been a pointillist, dotting the canvas with data points until a vivid and undeniable truth emerged. Her genius was both a weapon and a curse, a blade honed so sharply that it cut through meaning and left only apathy in its wake.

She sipped her drink with languid ease. If the world crumbled around her, she’d merely step over the rubble, unbothered and unchanged.

Ethan leaned against the doorway, studying her. “If I didn’t know better, I’d think you were meditating.”

She arched a brow, her smirk faint but cutting. “And if I didn’t know better, I’d think you were here to waste my time.”

He stepped inside. “Wait. We’re going? Now? No foreplay, we just…”

Diana set her glass down with deliberate precision, her gaze pinning him like a butterfly to a corkboard. “Time waits for no one, Imperialist. We’re leaving.”

She rose gracefully, a dark crimson cloak swirling around her. Without another word, she strode past him, her boots clicking softly against the stone floor. Ethan followed, his curiosity piqued despite himself.

They strode down the grand halls of Castlemartin reaching a central rotunda. Its domed ceiling soared high above, a marble fountain, twin angels poised in eternal servitude—one pouring water from an ornate urn, the other catching it in a basin. The gentle trickle echoed in the vast space, a haunting melody that softened the weight of the mansion’s mysteries.

Diana didn’t spare a glance for the grandeur. She moved with singular purpose, her cloak billowing behind her as they passed through a grand archway toward the ARCLIGHT chamber.

“We’re here.”

“And you’ve done this before, Diana?”

“I’ve seen a thousand stary nights, Imperialist.”

“And why are we doing this in the middle of the night?”

“If you must know, your brain produces chemicals that introduce specific behavior responses to the sensory inputs you’re about to encounter. It’s blind and deaf. It relies on stimuli to learn what to do in response to these chemical experiences. When ARCLIGHT puts you in hypothetical situations that feel real, it modifies our brains. You need to be sharp. Our minds are sharpest when the rest of the world is asleep. Anyway, it’s the people in our dreams that give us the best company. There’s more life than just what we see. Still think you’re ready?”

“I’m ready,” he said.

“I doubt it.”

He too had his doubts about the machine. “Claire already briefed me. Seriously Diana, I’m ready for whatever this is.”

She glanced back at him with her dull eyes as she scanned her finger to open the metal doors. The doors to the simulator room slid open with a hiss, revealing a vast expanse of desert dunes under a simulated star-filled sky. The sand beneath their feet was soft. The walls were a seamless expanse of black, interrupted only by thin, glowing lines that pulsed with life. The air was thick with the hum of dormant
energy, a low vibration that resonated in Ethan’s chest.

Diana shed her long cloak, revealing black vinyl pants and a black halter top that clung to her tightly and too short to fully cover her stomach. Ethan tried not to stare, but she somehow caught him.

“Pay attention, Ethan. This is ARCLIGHT,” she said, her voice reverent. “A place where time and space collapse.”

Ethan looked around, marveling at the endless dunes. “It feels… real.”

“Careful with that word,” Diana said, her tone almost softer.

She gestured to two leather chairs sitting atop a dune crest in the distance, connected by a web of wires to a machine that hummed with latent power. “Sit down,” she said, her eyes gleaming. “We need to go back to the beginning.”

“The beginning of what?”

“The creators of the labyrinth—Der Kreis.”

“Why look at the past? I thought we were supposed to assess future scenarios. Evaluate the unknown unknowns.”

“The world is not as you think you know it, Ethan. You need to see this first. How it all began to understand where we are today.”

“So, where exactly are we going?” he asked as she began to untangle the wires and prepare their two viewing chairs.

“Right now, just shut up and sit in the chair, Imperialist.”

Above, a domed ceiling projected an endless night sky, the stars bright and unblinking. It was as if the universe itself had been captured within these walls, nostalgia not lost on Ethan from his time in middle school inside the Liberty Science Center’s Jennifer Chalsty Planetarium back in New Jersey.

Ethan hesitated, his eyes narrowing. “And what exactly am I supposed to see?”

“Everything,” Diana said simply. She moved to the console, her fingers dancing over the controls. The machine responded with a soft hum, its lights next to him intensifying.

Ethan sank into one of the chairs, the leather cool against his back. Diana approached, holding a set of electrodes.

“Hold still. I need to connect these to your temples,” she said leaning over him while he lay back in the reclining chair. “Stop fidgeting.”

Every inch of her body a study in dangerous allure, the black halter top neckline plunging enough to reveal the smooth curve of her chest, which hovered mere inches from his face. Her shiny black vinyl pants caught the dim light, highlighting her legs and hips in glossy perfection.

Her scent was intoxicating, a mix of danger and desire—it filled his senses, making it hard to focus on anything but her. Her hair, a dark waterfall, occasionally tickled his cheek as she worked, her hands steady as they attached the delicate nodes to his temples.

“I said hold still, Imperialist,” she murmured, her voice low, sending shivers down his spine. Her fingers brushed his skin, light as a whisper, but enough to make him hyperaware of every point of contact. She shifted again, her chest grazing his shoulder.

“Comfortable?” she asked, though the smirk on her lips said she knew the answer.

Ethan’s pulse quickened, but he kept his expression neutral. “I’ll let you know.”

Diana attached the final node to herself and took the chair beside him. “ARCLIGHT will reveal a history only a select few know. You still think you’re ready?”

He gazed up at the vast array of stars, his resolve hardening. “I’ve faced worse.”

“Again. I doubt that.”

She hadn’t known his brush with death while in the Foreign Service..

“Just try to relax. This is where it gets a bit fucked up,” she said as the machine turned on an extremely low 5Hz theta wave frequency, perfect for deep meditation.

The lights dimmed, and the stars above seemed to grow brighter, their light pulsing in time with the machine’s hum.

“I’m going to start counting down from ten,” Diana said. “Right now, you need to shut up, calm down, and let go. I’ll talk us both into the right state while the neurotransmitters do their job.”

Ethan’s eyes fixed on the crescent moon hanging low in the inky sky, a cold sliver of light mocking his unease. He leaned back into the chair, its cool surface a stark contrast to the heat pulsing through his body. His hands gripped the armrests with a force that made his knuckles ache. What if he didn’t come back from this? What if this was some elaborate trick—a way to drug him into compliance? He couldn’t
forget the deliberate way she’d switched the nodes, her expression unreadable.

His chest tightened. Relax? Impossible. But Diana’s voice broke through his spiraling thoughts, low and measured.

“How are you doing, Ethan? Still good?” she asked glancing over him as she lay back in the chair next to him.

“I’m not going to die, am I?”

“Ten.”

~~~~~~~

From The A Spy Inside The Castle by M. B. Courtenay. Copyright © 2025 by the author and reprinted by permission.

A Spy Inside The Castle by M. B. Courtenay was published today December 9 2025 by Castlemartin and is available from all good booksellers, including