Chapter 12: The moment Evelyn's footsteps fade, Humphrey locks the chamber door and strides to where Bree is bent over the restraints, her ass jiggling with each mechanical thrust. 'Open,' he commands, shoving his cock past her lips just as the machine slams home, making her gag around his length while her pussy clenches violently around the steel shaft.
The sterile chill of the SPRINT chamber seeped into Bree’s skin, a stark contrast to the frantic heat building inside her as the machine’s slick piston hammered relentlessly into her cunt from behind. Strapped prone, hips elevated, wrists buckled down, she could only writhe against the restraints as the relentless slide of cold metal inside her stoked a fire Dr. Park’s detached monitoring couldn’t touch. Her moans were stifled against the padded headrest, sweat beading on her temples. On the monitor, her vitals spiked erratically – heart rate a frantic drum solo, neural activity a chaotic fireworks display. "Subject Bree," Humphrey’s calm voice crackled over the intercom, "Peak neural response plateaued at 98%. Initiating refractory period assessment protocol. Maintain focus." The piston slowed to a deep, grinding pulse, designed to prolong the peak without release, a torturous plateau. Bree gasped, her body clenching violently around the intrusion, teetering on the unbearable edge. "Dr. Park," one of the other researchers’s voice, clipped and devoid of inflection, cut through the intercom static, "Your presence is required immediately at Station 3. Anomalous biofeedback reading from Subject Carter. Requires your direct assessment." A beat of silence. Then Park’s reluctant, "Acknowledged. Monitoring on auto-log. Be brief." The heavy chamber door hissed shut behind her.
Silence, thick and charged, broken only by the machine’s rhythmic whir and Bree’s ragged breaths. Humphrey moved. Fast. Not towards the console. Towards her. The clinical detachment evaporated, replaced by a predatory intensity Bree felt before she saw it. He rounded the machine, his polished shoes loud on the sterile floor. His eyes, dark and burning, locked onto hers. No words. Just the rasp of his zipper cutting through the humming air. His cock sprang free, thick and already fully hard, flushed dark, veins prominent under the harsh lights, the head glistening. He fisted the base, the sight savage and primal.
He didn’t ask. He didn’t hesitate. Grasping a handful of her hair, he yanked her head back, the leather restraint biting into her forehead. Her cry was muffled as he drove his cock past her lips, shoving deep into her throat in one brutal thrust. She gagged violently, tears springing instantly. "Open wider, Subject Bree, and breathe through your nose" he growled, his voice raw gravel, tightening his grip in her hair until her scalp screamed. He pulled back, letting her gasp a wet breath, then slammed forward again, filling her mouth, stretching her jaw, the thick head bumping the back of her throat. Her eyes streamed, vision blurring.
The machine behind her chose that moment to surge. Its piston rammed home with renewed, punishing force, jolting her entire body forward onto Humphrey’s cock. It triggered a reflex, her throat muscles clamping down hard, milking him, making him groan – a low, feral sound that vibrated through her skull. He matched the machine’s rhythm perfectly. As the piston withdrew, he pulled his cock nearly free. As it slammed brutally back inside her, impaling her on cold steel, he drove his cock just as deep down her throat. Thrust for thrust. Pound for pound. Her world narrowed to the brutal invasion front and back – the hard, unyielding machine piston fucking her dripping cunt, the thick, hot flesh stuffing her throat, the salty-bitter taste of pre-come flooding her mouth, the sting of her scalp where his knuckles were white in her hair. Her moans were reduced to choked, wet gurgles around his cock.
He looked down, his glasses reflecting the blinking console lights, watching himself disappear between her stretched lips, watching her body buck and spasm as the machine drilled her. "That's it, take it," he rasped, his own breath coming in harsh pants. "Feel both. Feel the machine. Feel me. Show me what only you can fucking take." He pistoned his hips, driving deeper with each stroke, his balls slapping against her chin. Spit and tears slicked her face. The machine maintained its brutal cadence, the piston head grinding against her deepest spot, triggering involuntary convulsions that squeezed his cock buried in her throat. He grunted, a sound of pure, savage approval. "Yes. Your cunt clenches... your throat clenches... fucking perfect responsiveness. Keep breathing." His thrusts grew harder, faster, matching the machine’s escalating force with raw, human need. He was using her mouth like another orifice, fucking it with the same detached, intense focus he used to calibrate the machine, yet charged with a dark, possessive hunger that terrified and exhilarated her.
He leaned over her restrained body, his lab coat brushing her back, his voice dropping to a guttural snarl directly into her ear, "Now come again, Aubrey. For the machine. For my cock. Now." His command, the dual violation, the sheer overwhelming sensory overload – it detonated her. Her orgasm ripped through her, violent and silent, her scream trapped around the thick shaft stuffing her throat, her body seizing, clamping down in agonizing spasms on both invading forces. Humphrey roared, feeling her throat convulse wildly around him, feeling the machine piston pound into her contracting cunt.
"FUCK!" he bellowed, his rhythm fracturing. His hips snapped forward, burying himself to the root as his cock pulsed, jetting hot, thick spurts of come straight down her gullet. She choked, swallowing convulsively, her body still wracked by the machine’s relentless fucking and the aftershocks of her own climax. Humphrey held himself deep, grinding his cockhead against the back of her throat as he emptied himself, his harsh breaths echoing in the chamber over the machine’s steady, indifferent whine. He slowly pulled his slick cock free, a strand of saliva and come connecting it to her bruised lips for a second before snapping.
He didn’t look at her face. His gaze was fixed, intense and calculating, on the main monitor where her neural activity graph had just spiked into an unprecedented, jagged peak. A muscle twitched in his jaw. "Anomaly confirmed," he breathed, the scientist reasserting itself even as he tucked his softening cock back into his trousers, the zipper’s rasp shockingly loud. Just as he began to release her restraints, the chamber door hissed open. Park stood silhouetted, her expression unreadable. Humphrey’s hand, still trembling slightly, adjusted his glasses as he turned to face her. "Subject exhibited an extreme refractory override event," he stated, his voice regaining its clipped neutrality, though his knuckles were still white.
Dr. Park’s sharp eyes scanned the monitors, lingering on the erratic oxygen saturation graph still pulsing red at 88%. "Her O2 levels fluctuated wildly, Alistair—down fifteen percent from baseline averages." Her clinical tone sliced through the sterile air as she tapped the screen. "That’s never happened mid-session without external interference."
Bree’s throat burned, the bitter aftertaste of Humphrey’s release thick on her tongue as she fought to steady her breathing against the restraints. "Just... choked a bit," she rasped, forcing a shaky smile while discreetly swallowing the last sticky remnants. "Swallowed wrong when the machine... shifted angles. Kept trying to breathe through my nose to keep from coughing…" Sweat slicked her temples as she avoided Park’s scrutinizing gaze.
Humphrey adjusted his glasses, his knuckles whitening again where they gripped the console edge. "Plausible," he conceded coldly, though his eyes flickered to Bree’s flushed lips. "Mechanical thrust vectors can trigger involuntary gag reflexes during peak cervical contact." He pointed to the neural readout. "Note the correlative spike in vagus nerve activity."
Park frowned, unconvinced. "Run the feed back. I want to see the exact moment her oxygen dropped." Her fingers hovered over the replay command.
Bree’s pulse hammered against the wrist strap—fuck, the cameras. Humphrey stepped smoothly between Park and the console, his voice like steel. "Irrelevant. The anomaly resolved. Proceed to post-arousal biomarker extraction." He didn’t blink. "Collect her vitals now, Evelyn. She will see she’s perfectly fine."
Silence hung, thick with tension. Park’s jaw tightened, but she turned toward the instrument tray. Bree exhaled shakily, the lie sour in her mouth as Humphrey’s stare seared into her—a silent promise. His thumb brushed a droplet of sweat from her collarbone, possessive and deliberate. "Breathe," he murmured, low enough for only her to hear. "Just breathe."
The chamber door hissed shut behind Humphrey as he retreated to the observation room, leaving Bree trembling on the examination table while Park efficiently detached electrodes. The cold metal stung her bare thighs as Evelyn’s latex-gloved fingers pressed beneath her jaw, checking lymph nodes. "Swelling," Park noted flatly, her eyes sharp on Bree’s reddened lips. "Your vocal cords are strained, Aubrey. Unusual for a pelvic-focused stimulus." She snapped off her gloves, the sound loud in the suddenly quiet room. "Look at me. Did something happen when I left? Did Dr. Humphrey enter the chamber? Push you beyond protocol?"
Bree’s throat tightened, the phantom pressure of his cock making her swallow reflexively. "No," she rasped, forcing her voice steady despite the raw ache. "Like I said, the angle... it triggered a gag reflex. I may have screamed a bit more than usual, it was just such a different position from our previous sessions" She avoided Park’s searching gaze, focusing on the blinking red light of the deactivated SPRINT machine.
Evelyn sighed, a rare crack in her clinical armor. "I’ve known Alistair twenty years. Brilliant? Undoubtedly. But he fixates. Sees subjects as data points, not people with limits." She leaned closer, her voice dropping to a harsh whisper. "He’s obsessed with your responses, Bree. I see it in how he analyzes your sessions, pushes the parameters further each time." Park’s hand briefly touched Bree’s wrist, a startling warmth. "I’m afraid he’ll push you past what you can physically or mentally endure. And I’m afraid you’ll let him."
Bree tugged her shirt on, the fabric rough against her hypersensitive skin. "I know my limits," she retorted, sharper than intended. "This is my choice. My body." The defiance felt thin, echoing in the sterile space.
Park gathered her tablet, her expression weary. "Just be certain it’s your choice, Bree. Not his obsession wearing you down." The door clicked shut behind her, leaving Bree alone with the humming machines and the fading echo of Humphrey’s command. Just breathe. She touched her throat, the memory of his grip, his thrusts, colliding with Park’s warning. A cold knot of doubt tightened in her stomach as she walked out.
The sterile hallway lights buzzed overhead as Bree walked away, her thighs still slick, her throat raw. The phantom weight of Humphrey’s cock seemed to linger, a brutal counterpoint to Park’s chilling warning. Was it her body, or was Humphrey’s hunger becoming hers?
Back in the dimly lit observation room, Humphrey moved with predatory speed. His fingers flew across the console, isolating the segment where he’d entered the chamber, where the camera had captured him shoving his cock down Bree’s throat while the machine pistoned her from behind. He encrypted the raw footage, sending it to a secure private server only he could access. Then, with surgical precision, he corrupted the original feed’s timestamps and injected a simulated signal glitch into that exact timeframe, making it appear the cameras had suffered a temporary malfunction – static snow and distorted audio perfectly obscuring his transgression.
The heavy door hissed open. Dr. Park entered, her expression granite, eyes narrowing at Humphrey hunched over the consoles. "You entered the chamber, Alistair," she stated flatly, crossing her arms. "Explain. Immediately."
Humphrey straightened, turning slowly, his face a mask of cool professionalism. "Naturally," he replied, his voice devoid of inflection. "I observed a significant respiratory anomaly via the vitals feed – oxygen saturation dropping precipitously." He gestured towards the corrupted data screen displaying the simulated malfunction. "Subject Travis exhibited signs of distress consistent with choking. I intervened to ensure airway patency."
Park’s gaze flickered to Bree’s still-elevated O2 stats on another monitor. "Choking? During pelvic stimulation?"
"Indeed," Humphrey confirmed, adjusting his glasses, the gesture calculated. "Upon entering, I found her gag reflex triggered, likely by the machine’s deep anterior thrust vector coinciding with cervical contact." He paused, letting the clinical jargon hang. "However, closer proximity revealed the physiological response – vocal cord spasms, tear production – correlated directly with her arousal peak immediately preceding." His eyes met Park’s, unblinking. "It wasn’t obstruction. It was an extreme manifestation of her refractory override sequence. A critical data point obscured by camera failure, but validated by direct observation." He tapped the glitched feed emphatically. "She was fine. Overwhelmed, perhaps. But fundamentally responsive."
Park stared at the snowy screen, then back at Humphrey’s impassive face. Suspicion warred with his clinical logic, her mouth a tight line.
Park’s eyes narrowed, sharp as scalpels dissecting his bullshit. "You let her choke, Alistair," she hissed, stepping closer, the ozone scent of the machines sharp between them. "You didn't intervene to ensure she climaxed safely. You let her struggle, gag. To see how far her 'unique' fucking receptivity would stretch." Her knuckles were white on her tablet.
Humphrey’s jaw tightened, a ripple beneath the clinical mask. "The SPRINT machine," he countered, his voice cool steel, "is programmed to recognize physiological limitations in real-time. Its algorithm dictates when to pull back." He gestured sharply at Bree’s vitals, still glowing steadily on the monitor. "It didn’t pull back, Evelyn. Because it hasn’t found her threshold yet."
He leaned over the console, his reflection fractured in the dark screens. "Her neural patterns during that episode… the persistence beyond expected tolerance… it wasn't distress. It was response. Raw, unfiltered proof the machine can be pushed further than we conceived." Passion bled into his clipped tones. "She didn't break. She adapted."
Park slammed her hand flat on the console, making dials jump. "You're gambling with her body, her mind, chasing ghosts in your data! She’s human, Alistair, not your fucking breakthrough prototype!" The accusation hung, thick and suffocating.
Humphrey turned fully, his intense eyes locking onto hers, stripped of pretense. "Exactly. She’s human. And she showed us the machine can learn to navigate peaks we deemed impossible." He paused, the hum of servers the only sound. "Her limits," he whispered, the word charged, "are the new frontier."
Park’s knuckles pressed white against the console’s edge, the sterile light glinting off her wedding band. "Her limits?" she hissed, the word scalding. "Is that what you call nearly choking her unconscious while the machine fucked her senseless? Or is that just the label you slap on your reckless god complex?" The hum of the servers seemed to swell, filling the charged silence.
Humphrey met her fury with unnerving calm, his glasses reflecting the jagged spike still frozen on Bree’s neural readout. "Obsession implies irrationality, Evelyn. My focus is empirical." He tapped the corrupted feed display. "The data, despite the malfunction, proves resilience we haven’t cataloged. We calibrate the machine to human thresholds. She is redefining them." His gaze flickered briefly towards the chamber door where Bree had exited, raw and trembling. "Her physiology is the key."
"Bullshit, Alistair," Park snapped, stepping closer, the scent of antiseptic sharp between them. "You crossed a line today. A dangerous, unethical line. Or did scrambling the feed wipe your memory of how you used her? Because I know you don’t want me to see whatever it was that you did or didn’t do when you went in there." Her voice dropped, dangerous. "Tell me this, Doctor Visionary: would you dare run these same extreme protocols? Push the SPRINT to these levels," she jerked her chin towards Bree’s brutalized vitals log, "and physically intervene with another subject like you did with her? Would you shove your fingers on some stranger’s cunt while the machine hammers their ass, just to see if they can ‘redefine thresholds’?"
Humphrey’s expression didn’t flicker, but a muscle tightened along his jaw. He adjusted his glasses, the movement precise. "Only," he stated, his voice clipped and devoid of hesitation, "if preliminary data demonstrated the same anomalous predisposition for extreme receptivity and refractory override observed in Subject Travis." He paused, his intense eyes locking onto Park’s. "The unique neurological signature. The documented lack of inhibitory response. Like Bree."
A cold, mirthless smile touched Park’s lips. She straightened her lab coat. "Good." The word was ice. "Because we’ll get to see for sure just how ‘unique’ your star subject truly is." She turned towards the door, pausing with her hand on the handle. "The new male subject arrives in two days. Phase Two begins. Let’s see if he surprises you as much as she did."
Park’s challenge hung in the sterile air like ozone after lightning. She moved towards the door, then paused, turning back sharply. "Speaking of surprises, Mark Olsen’s next session is scheduled for Thursday." Her voice was deliberately neutral. "The protocol requires testing multiple orgasms, just like Bree’s today. Given your… hands-on approach with her, do you intend for Subject Travis to participate again? To assist?"
Humphrey whirled from the console. "Assist?" The word was a snarl, raw and dangerous, shattering his clinical detachment. "Is that what you think I was doing in there with her, Evelyn? Assisting?" He took a step towards her, his posture rigid, the tendons in his neck straining against his collar. "Or do you imagine something sordid?"
Park didn’t flinch. "I imagine you crossed a professional line we spent years drawing, Alistair. I imagine you are personally compromised by that subject." Her gaze was unwavering. "And I need to know if your compromised judgment extends to involving her in Olsen’s testing."
"Compromised?" Humphrey slammed his hand down on the console, making monitors jump. "My judgment is focused on unprecedented physiological data – data she provides!" Spittle flecked his lips, his voice rising. "You’re deliberately misconstruing my intentions towards Bree. Reducing groundbreaking observation to some… some fucking tawdry attraction!" His glasses slid down his nose, revealing eyes blazing with fury and something close to panic. "Get out, Park." The command was low, venomous. "Leave. Now."
Park held his gaze for another taut second, the air crackling with his rage. Without another word, she turned, the chamber door hissing shut behind her. Humphrey stood trembling, knuckles white where they pressed against the cold metal console, a thin trickle of blood welling where his clenched fist had split open on a sharp edge. The jagged peak of Bree’s neural readout still glowed accusingly on the screen.