Rosa could hardly breathe. She bent over the silkworm cascade and touched trembling fingers to the sign. The word made her mind ache. She read, “MASS… that’s what….” The words wouldn't come. Smaller type below the acronym read ‘Models of Artificial Simian Sentience’. The implications made her knees weak. She put her hand on the wall to steady herself.

Selina tore the small sign off the door. “Evidence,” she hissed, snapping Rosa out of her stunned silence.

A sharp bark cut through the air. Rosa and Selina turned back to the macaque, its piercing amber gaze sending a shiver down Rosa’s spine. The creature's glossy fur rippled in the October breeze, giving it a regal, untamed presence. Its pronounced black crest added a touch of dark elegance, a crown fit for a beast.

It watched them with an eerie, quiet intelligence, its face nearly expressionless save for the faintest twitch at the corner of its mouth. Rosa’s heart picked up its pace, as if the creature were appraising her, weighing her in some silent, unknowable way. She swallowed, glancing uneasily at Selina. “We shouldn’t stay here,” she murmured, voice tight with apprehension.

Selina shuddered, rubbing her arms as though to brush off the invasive chill. “It's Rowan isn't it?”

Rosa nodded, looking grave. “I think so. Can't be too many macaques roaming darkest Devon.”

“Are we stuck with a monkey now?” Selina stuttered. Her voice was shaky, a brittle edge of disbelief cracking through. Her eyes drifted unwillingly to the broken remains of the drone, lying where the macaque had smashed it, the same drone that had coldly scanned her retinas moments before. “That thing looked right into me,” she whispered with a note of raw unease. “It felt like… I don’t know, like it was violating my private thoughts.”

She glanced again at the macaque’s long face, its sharp, penetrating eyes, and felt her skin prickle. There was something in its look that felt unsettlingly human, as though it understood them on a level they couldn’t fathom. It made her feel even more exposed.

As Rosa stared, she felt all the sensations of her recent dreams flooding back into her, sensing this creature had a purpose, had intent. The macaque’s gaze held hers for a moment, then it darted off around the building with a flash of ebony fur.

Rosa stepped forward instinctively, only to see it pause just around the corner, peeking back with those piercing eyes.

“It wants us to follow,” she said, a note of incredulity breaking through her voice.

They crept around the hulking concrete building, following as the macaque darted ahead, seeming to know exactly where it was headed. The creature led them to a collection of skips and heavy industrial wheelie bins wedged into a shadowy corner. It sprang deftly onto the largest skip, glancing back at them with eyes that almost seemed to measure their nerve.

Selina squinted as the monkey she assumed to be Rowan swung up to a narrow ledge formed by a sealed-up vent box further up. "It’s been here before. Knows exactly where it’s going."

Rosa nodded, chewing her lip. “You think we can do this?” She gestured to the bins, layered in grime and dented with use.

Selina stared at her. "You mean - climb? Up there?”

Rosa examined the wall. Exposed pipework ran up the corner, and further above, the ventilation duct poked out beside what might have once been a window, now bricked up. It looked forbidding, but with the pipes and corner edge for handholds, it was reachable.

“We don’t have much choice,” Rosa replied, her voice tight. “That macaque’s not waiting for us to overthink this.”

Selina shot her a look. “So what? He probably lives up there. I don’t like it. I really don’t. This place is unnerving.”

The macaque, perched high above on the vent, watched them intently, as though daring them to follow. Then it scrambled up the piping, disappearing over the edge of a small inspection platform just short of the roof.

Selina shook her head, muttering, “Can’t believe I’m doing this.” She placed her hand gingerly on the skip’s edge, testing the metal beneath her, then pulled it away quickly, sniffing at her fingers.

As they hoisted themselves up, the two women felt the wobble of the bins’ locked wheels. Rosa reached for the exposed pipes along the wall, fingers gripping the cold, painted metal. Each pull felt precarious, every creak from the ductwork uncomfortably loud.

She glanced down at Selina, who was struggling to find her footing. “How’s it going?” she whispered.

“Oh, just fantastic,” Selina replied, wincing as her foot slipped slightly. “Never thought I’d spend my day chasing a monkey up a fortress wall.”

At last, they reached the grey, steel platform, probably used for monitoring the contents of some enclosed units here on the wall. Breathless, they clambered onto the guard rail, able now to scramble over a gutter to the roof. The macaque was waiting. It gave a little huff and then trotted off along the flat rooftop, vanishing up a fire escape to a higher level. Rosa and Selina exchanged a look, nerves taut, before following.

At last, they reached the highest part. The monkey stopped, giving them a moment to take in the view. The Devon countryside was spectacular: fields interspersed with golden woodlands; undulating moorlands with rocky tors, stretching all the way to the sea.

On one side below, within the building's protected perimeter, was a seemingly forgotten area - a twisted maze of animal pens, overgrown with tangled weeds and wrapped in twisted, rusted bars. Rows of cages lined the ground, some still faintly marked with scratch marks and tufts of fur clinging to the bars. It was as if the place had once been an impressive animal care centre, a compact zoo with all the right facilities, now decayed into something haunting and abandoned.

Selina wrapped her arms around herself in her usual self-reassuring way, her gaze darting over the abandoned cages. “Looks like a mini zoo. Whatever, that part of this place hasn't been used in a long time.”

“Maybe they moved the animals on,” Rosa whispered doubtfully, unable to tear her eyes away from the scene. A sickening sense of confinement hung in the air, as though whatever had been held here had never truly escaped. Just then, Rowan uttered a gruff, low bark drawing their attention to a raised frame in the roof.

Rosa spotted a dirt-streaked skylight set into the rooftop not far from where they stood. Followed by Selina, she crossed and knelt, peering down into a pale corridor below. She was about to move on, when two lab workers in white coats wheeled a small metal cage along the hall, the squeak of the wheels just audible through the glass. Inside, a small capuchin monkey crouched, its eyes darting with fear. There was a shaved patch on its head, an elongated scar - twisted in the shape of an "S," or perhaps an infinity symbol.

“Are they really doing this to it?” Selina murmured, her voice edged with revulsion. “That’s way beyond tagging.”

Rosa’s gaze sharpened as she studied the scar. “It’s not just a mark… it looks invasive, like something’s inside.” The sight triggered a memory - the days in the lab, staring at rows of letters - ‘five pages mostly made up of the letter S’. The eerie sibilant ssssseeebbbusss.

Suddenly, the capuchin below jerked its head up, eyes locking directly onto hers through the grime on the skylight. Rosa felt herself freeze, transfixed, as though the animal were staring right into her. With a sudden, visceral energy, it lunged against the bars of its cage, screeching with an intensity that seemed to drill through her skull, vibrating into her bones.

The lab workers fought to hold the cage steady, but the capuchin’s eyes didn’t waver, filled with an almost accusatory awareness. It was as if it were trying to communicate with her, those wild eyes drilling into her mind’s eye. She squeezed her own eyes shut, trying to shake the feeling, but her pulse drummed and something in her mind snagged on that symbol. Her thoughts circled it, tracing the lines again and again, like compulsively running a finger over a scar.

Selina ducked out of sight, but Rosa seemed mesmerised, unmoving, until her companion dragged her down out of sight.

A sharp vibration caught her attention. She pulled her phone from her pocket, but the screen was unreadable - lines of symbols scrolled past, jagged and glitched, too quick for her to make sense of. The phone heated up in her hand, and she felt a dark presence she’d sensed before, as if slipping through the glass, winding into her thoughts with a chilling clarity.

If you spot this story on Amazon, know that it has been stolen. Report the violation.

Hoo…

The air grew thick and syrupy, each breath feeling like it dragged her deeper into a suffocating dream. The world stilled, suspended around her as if holding its breath, waiting. Her mind flickered over fractured images, half-formed thoughts - lines of code, letters scrawling across a wooden desk. Every nerve in her body hummed with the sensation of falling away from herself, sinking into something deeper, darker, inescapable.

Hoo… Who?

Rosa’s inherent need to make sense of patterns - the obsession that had once kept her staring at random shapes until they made sense, turned against her. She felt herself slipping, caught in a spiral of symbols and disconnected thoughts, blurring as she lost the ability to parse what was real. Who? Who's there?

And then it was there, deep inside her awareness, an alien intelligence. “Who’s there?”

She knew without question - LumiGard. “Who’s there?” Her mind echoed the question, searching for a shape, a voice. But this wasn’t the LumiGard she’d known before - it was darker, a shadowed version with a colder, twisting intent that felt very sentient, prying into her memories with the delicacy of a scalpel.

The pressure deepened, dragging her back through layers of her life as if unspooling her mind thread by thread. Flashes of her grandfather, his gentle, weathered hands as he showed her old black and white photographs of the capuchin enclosures in Africa, the calm cadence of his voice as he spoke of the intelligence he saw in their eyes. She could almost smell the dry, warm air, the scent of wood and dust and animal fur, grounding her before the images twisted, snapping her back to her childhood home. Then her current home - the silver mine house her parents had gifted her when they moved back to London, unable to settle to rural life.

Then, the sensation tightened, drawing her deeper, and one memory rose to the surface with vivid clarity: waiting in a darkened theatre, the anticipation crackling in the air. She remembered that velvet curtain unfurling with a long, echoing “ffvvvvvvvpppsss” - a breathless moment, a pause before reality changed.

And beyond the curtain, it came. A figure - hooded, draped in shadow, a monkey with skin pulled tight over a skull with sharp, unnatural angles, and that shroud of darkness. The hood concealed everything but the intent, amber eyes, watching her, drilling into her, demanding her attention.

Her pulse quickened, every instinct urging her to pull away, yet the force pressed harder, winding deeper like a tightening noose. She felt LumiGard pushing into her mind, an invasive presence she fought to resist. Her thoughts thrashed for clarity as her vision blurred, dissolving into a familiar scene: the monkey enclosure she’d studied so often, now bathed in a sickly, unnatural light, empty except for a single keyboard.

With a slow, deliberate gait, a lone black monkey approached, settled before the keys, and began to type. Its skeletal fingers tapped with eerie precision, each keystroke filled with meaning. Letters flickered onto the screen, coalescing into one line that drew her in: a question she couldn’t ignore.

"Who’s there?"

The first line of Hamlet. Waiting.

A guttural hiss yanked Rosa from her trance. She blinked, and there was Rowan - the black Sulawesi crested macaque - silhouetted against the sky, his golden eyes fixed on the horizon with a look like some wild moon-watcher from the dawn of time. In one swift motion, he snatched her phone and lifted it high above his head in silent triumph. For a heartbeat, he held it there, his gaze far-off, as if communing with something beyond. Then, he smashed it again and again on the roof, pieces of glass and plastic flying in all directions before, in a curling arc, he hurled what was left of it skyward. The broken phone spun through the pale light, glinting as it soared before plummeting back down, shattering against the rooftop with a stark, echoing crack. Rowan stood over the fragments, his dark fur bristling, his eyes still locked on the spot, as if he alone understood the meaning of what he’d done.

“Rowan…” Rosa’s voice trembled, head throbbing as she looked into the macaque’s eyes.

Selina scrambled over beside her, her face tight with alarm. “Rosa, are you okay?” she whispered, her voice edged with disbelief. "You looked… completely out of it for a moment there.” She glanced warily at Rowan and risked a peep at the skylight. “What is this place and what are they doing to that poor macaque?”

“Cebus… I think it’s… a cebus monkey, ” Rosa said softly, feeling a chill creep up her spine.

Rowan gave a low screech, sharp and angry, as though trying to pull them back to the present. He turned, dashing off to the edge of the rooftop. Rosa followed its gaze and spotted a single, narrow staircase with flaking green paint, leading down.

Selina shot her a wary glance. “Do we really want to go where it’s taking us? These people… they don’t exactly look like they’re running a petting zoo.”

Rosa hesitated, her gaze lingering on the rim of the skylight, a blur of dreams and virtual memories clouding her mind: the bald monkey, the pages of esses, the chilling Morse code message flashing in her darkness. “After everything that’s happened, I can’t ignore all this. I think I have to do this.”The macaque chattered again, more insistently this time, then disappeared down the staircase. Rosa took a breath, readying herself. “Come on. We need to see what they’re doing.”

With a reluctant groan, Selina followed, feeling each step lead further into the unknown. The narrow stairwell shifted slightly with their weight, every creak of the metal vibrating through their bones, amplifying Rosa's urge to count her footfalls. The hum of machinery grew louder as they descended, a low, droning pulse that seemed to seep through the walls. Her hand brushed against something cold and wet on the rail and she instinctively pulled back, wiping her fingers, an urge to shake off the contamination rising within her.

At the bottom, the macaque led them to a small window, its glass almost opaque with grime and dust. Rosa wiped a small patch with her finger, leaning toward the glass, peering inside. Rows of cages lined the walls, some empty, others holding still shapes - monkeys, curled into themselves, unmoving. She felt a sickening realisation dawning.

Selina’s voice was barely a whisper. “What's going on in this place?”

Rosa shook her head, swallowing hard. “Something… something MASS didn’t want anyone to know about.”

Their monkey guide, now pressed close beside them, let out a low, guttural sound, its eyes narrowed.

The space inside was cluttered with blinking machinery, heavy metal doors, and shelves lined with equipment. In the shadows, Rosa spotted a metallic glint, then focused in horror. A set of restraints - fitted to something small and helpless.

“Is that… a black macaque?” Rosa breathed, her voice barely audible.

Selina’s face twisted from intrigue to revulsion. “Whatever they’re doing here, it’s not rehabilitation.”

As Rosa’s gaze flickered to Selina beside her, the sign she had tucked into her waistband caught her attention. The bold letters “MASS” on their red background seemed to leap out at her, and the chilling phrase: Models of Artificial Simian Sentience. The words held a new meaning now, the depth of their significance sinking in. This was what they were doing to these monkeys. This was MASS.

A low, insidious hum drifted into the air, vibrating from somewhere overhead. A drone. The macaque on the roof gave a shrill, panicked cry and bolted, vanishing over a ledge.

Rosa’s heart lurched. “Selina, we need to get out - now.”

The drone’s camera glided over the grounds, its mechanical eye scanning for any sign of life. They ducked low, pressing themselves against the rough surface of the roof, feeling ill-concealed and vulnerable.

Rosa’s pulse quickened as the drone hovered closer. “We can’t let it see us,” she breathed, glancing at Selina, whose wide eyes mirrored her fear.

They stayed still, holding their breath as the drone swung around, its whirring blades slicing through the air. Rosa bit her lip, willing herself to remain motionless, her heart pounding in her chest like a drum. The drone lingered a moment longer before drifting away, focusing on something deeper in the grounds.

Rosa pulled Selina away from the edge. “Now,” she hissed, urgency propelling them back the way they’d come. They moved cautiously along the narrow rooftop, each step a careful negotiation with the uneven surface beneath their feet. Rosa glanced over her shoulder, nerves prickling at the thought of being spotted.

They reached the far end of the roof, where a narrow ledge loomed ahead, covered in moss and littered with debris. The drop to the ground was daunting, several feet below, and a tangle of weeds and shadows obscured their landing spot. Rosa hesitated, eyeing the insufficient ledge that seemed slippery underfoot.

“Come on,” she urged, her voice low as she crouched at the edge. With a deep breath, she swung her leg over, feeling the damp surface soak into her jeans as she lowered herself. As she dangled momentarily, the ground felt impossibly far away, and the rush of adrenaline pushed her to grip tighter.

“Selina, hurry,” she called, glancing back. Selina was close behind, her eyes wide with apprehension as she mimicked Rosa's cautious movements. With a shaky breath, she took her place, finding her footing on the moist moss.

Rosa dropped down, landing with a soft thud in the overgrown grass below. The ground gave way slightly under her feet, and she stumbled but quickly steadied herself, scanning their surroundings for any sign of movement. “We have to keep moving,” she whispered urgently.

Selina followed, her descent more tentative, her foot slipping slightly on the way down. She hit the ground with a delicate grunt, but Rosa was already urging her on. They ducked low, slipping into the tall weeds, every rustle of grass and whisper of wind echoing in their ears as they moved swiftly and silently away from the looming structure. As they rounded a corner, Rosa froze.

Two men in dark uniforms prowled the grounds, their eyes scanning the area with military precision. Rosa felt her heart race as one of them stepped closer, peering off across the building's façade. His fingers grazed the shape of a gun at his hip. “We need to get around them,” Rosa whispered, her voice barely audible.

Selina nodded, her expression tense. They edged back, staying low and pressing themselves against the wall of the building, the sun casting long shadows across the ground. They waited, barely breathing, as the men exchanged low murmurs, their attention focused on the doorway with the silkworms.

“Now,” Rosa whispered again when the men turned away, and they dashed through the scrubby grass, every rustle feeling like a scream, but they pressed on, until they reached the gravel path leading back to the car.

As they neared the vehicle, Rosa glanced back, seeing the men now examining the doorway. “Quick!” she urged, sprinting toward the car. They flung open the doors and dove inside, hearts racing. Just as they settled in, the black macaque leaped into the back seat, chattering frantically, clearly sensing the danger.

“What the… ? Where did he appear from?” Rosa exclaimed, wide-eyed.

Without hesitation, Selina started the engine, her hands trembling. The engine roared to life, drowning out their fears. She floored the accelerator, gravel flying as they skidded down the industrial estate, the building receding behind them like a dark specter.

Rosa turned, her face pale as she watched the ominous structure fade into the distance, the dark figures stepping into the road, watching them go. “I don’t believe that place.” she whispered, disbelief lacing her voice. “They actually had a gun!”

Selina’s knuckles whitened around the steering wheel, her face set in grim determination. “Whatever MASS is, it’s no dream,” Rosa muttered “And whatever they’re doing there…” She swallowed hard, the weight of their discoveries pressing down on her. “I don’t think it’s legal.”