Investigation - Cover

Investigation

by Bisamrattan

Copyright© 2026 by Bisamrattan

Science Fiction Sex Story: Detective Riley Morgan is investigating the mysterious case of the Changed Women. Now, she has been captured and is about to find out everything she needs to know — first-hand.

Caution: This Science Fiction Sex Story contains strong sexual content, including Ma/Fa   Fa/Fa   Fa/ft   Mult   Consensual   Drunk/Drugged   Fiction   Crime   Horror   Workplace   Science Fiction   Light Bond   Gang Bang   Body Modification   Transformation   .

Riley came to, feeling dizzy and lightheaded. Fighting the urge to silly giggle, she moved her head. No pain or nausea, so she probably wasn’t hit in the head. She looked down and saw that her arms and legs were tied to the armrests and legs of a heavy, mounted chair in the middle of a dimly lit, windowless room. Oh, so she had been caught. She looked at herself. She was still wearing her neutral-looking civilian clothes, but her hidden underarm holster was gone. Welp, so they’ve searched her.

Her playful dizziness intensified. Riley smirked. Sensyl, no doubt. She had tried that drug at some of the sex parties she had attended. It’s the best thing to completely drop your restraints and release your inner sex beast. It was also the drug of choice for rapists because the drugged girls participated willingly and then lost their memories of the details, remembering only the wonderful sex they had. Riley chuckled. Will they rape her? She moved her eyebrows. Her recorder, disguised as a piercing ring, was still in place. Hopefully, they won’t figure it out and remove it. She’ll bring the evidence — if she makes it through.

The door in front of her opened, and three men entered. Two were featureless thugs, who stayed by the door, and the third was a small, nerdy-looking man who was clearly the boss.

Riley laughed and nodded.

“Hello!”

She knew him—not personally, but from the infodumps: Jack Shadow—most likely an alias—a mad scientist and a criminal mastermind. They did not know, however, that he was tied into this Changed Girls case. Nice. Even if this piece of information is the only one she brings out, her mission is already a success.

Jack smiled back dryly.

“Welcome, Detective Riley Morgan.” Oh, so their intelligence is equally good. She was not carrying her ID with her, of course. “My congratulations. You are the first agent who got that close to our depot ... to one of our many, many depots.” He slowly walked around her chair. “So, I suppose, you’ve came to get some answers to some pesky questions? About the Changed Girls, I guess? About your precious daughter, perhaps?”

Riley grinned at the mention of Changed Girls and smiled even more at the mention of Lila, still feeling the pleasant buzz from Sensyl. The mention of her daughter usually caused a pang of guilt and fear to pierce through her professional demeanor. But the drug had smoothed the edges of that pain, replacing it with a strange, pleasant warmth. She wondered if this was how Lila felt all the time now. Happy and free and ... warm. A small smile touched Riley’s lips before she could stop it.

“I’m here for answers, yes. And to stop this ... enterprise.” Her words came out more relaxed than she intended. Sensyl was doing its job well.

Jack laughed with a dry, rustling sound. “Stop this? My dear detective, we’re not criminals. We’re facilitators. We’re liberators.”

Oh, The Villain Speech! Good. Let him speak.

The word hung in the air: Liberators. Riley wanted to scoff, but Sensyl held her gently in its grip.

“Liberators?” She lifted her gaze.

“Of course! We return the purpose that women have lost in our crazy world. We remind them that they are sexual beings whose primary need is to have sex with any man around them. Just like in the happy, prehistoric, tribal times. Isn’t that nice?” Jack’s voice was smooth, almost hypnotic. Sensyl made it sound reasonable. Almost. Riley’s police training fought against the honeyed words, but her nipples tightened, and she felt the familiar warmth in her lower abdomen, the anticipation or a side effect of the drug, she couldn’t tell.

Riley’s professional veneer was cracking under the influence of Sensyl. Her usual steel-clad composure felt like a distant memory. This was dangerous ground. She knew what was happening to her body, her mind. She was a trained officer, experienced in interrogation, in resisting. But this was different. He wasn’t interrogating her; he was— persuading?

“So why the secrecy, Jack? If you’re all about liberation?” Her words dripped with a sarcasm that felt more playful than hostile. “Why kidnap unsuspecting girls and women, and return them a day later, brainwashed into sex addicts?”

Jack just smiled, a gesture that didn’t reach his eyes. “Society isn’t ready for our brand of liberation yet, detective. They still cling to old notions of shame and guilt. We have to prepare the ground, introducing a handful of women at a time, until the change takes hold from the bottom up, and this stupid society crumble.”

He moved closer and ran his fingers along her cheek. Unable to resist, Riley closed her eyes and pressed her cheek back against them. She almost moaned from the pleasure and arousal building up inside her.

Jack chuckled. “Sensyl. You can always count on it. Our first attempt. We thought we could alter the behavior chemically—and partially succeeded—but we didn’t manage to achieve a permanent effect. So, we had to look for another solution.”

She opened her eyes. “Permanent? So, your mission is to turn women—even teenagers!—into sex addicts permanently? Without asking if they want to be changed? You monster!”

He smiled. “I give them the life of purpose and endless pleasure. What did your bosses give you? The order to infiltrate enemy territory, where you could be maimed or killed? Who are the real monsters, huh, Riley?”

Oh, the classical rhetorical trick. But under Sensyl’s influence, it worked. Her mind began to justify that, indeed, maybe it was not all that bad. At least this way Lila would always be happy, even if the path to that happiness twisted her into something else.

Her traitor body responded. A throb pulsed between her legs, deep and insistent. She shifted in her chair, feeling the friction of the fabric against her suddenly sensitive flesh. The room felt warmer, the air thicker. Each of Jack’s words echoed in her ears, not just a challenge to her authority, but an invitation to a world of sensation she could feel stirring to life within her. Her police training, her very identity as a detective, was being systematically dismantled by a chemical and philosophical attack she wasn’t prepared for.

“So...” she heard herself say, her own voice sounding distant. “This ‘other solution’ of yours...” She swallowed, her throat dry. The main question she was after. She was terrified to ask, but her detective training plus Sensyl-emboldened curiosity won out. “What is it?”

He straightened up, beaming at her like a teacher at a promising student.

“You’re going to see for yourself, you are! You came for answers, and you’ll get them all, firsthand. It’s a pity you won’t remember the details.”

He gestured to the two thugs behind him. “Untie her.”

They removed the ropes from her wrists and ankles and stepped back.

He looked at her. “Stand up and undress. Completely. Naked.” He smiled. “You may keep your jewelry on.”

This was it. The point of no return. She knew she should fight. Resist. But that will bring her to the same point, only beaten and forced to do it anyway, for sure. And— her body screamed at her to obey. Sensyl had transformed a direct order from her captor into the most appealing suggestion she’d ever heard. To shed her skin, her armor, the identity that confined her. The promise was liberation.

Her fingers, trembling slightly, went to the hem of her shirt. They fumbled with the button on her jeans, the simple act feeling impossibly intricate. She peeled away the layers of her life—the convenient sneakers, the practical cotton of her bra, the sensible panties. With each item that fell to the floor, she felt another brick of Detective Riley’s wall crumble. The cool air of the room kissed her skin, raising goosebumps that had nothing to do with temperature and everything to do with raw exposure.

She stood before them, naked save for the recorder ring in her eyebrow and Lila’s locket, the silver cold against her chest. A strange detached part of her mind cataloged the scene: Detective Morgan Riley, 30, SVU, stripped bare in a secret warehouse, about to undergo God-knows-what procedure at the hands of a madman. The professional observation was a flimsy shield against the rising excitement and arousal.

He admired her firm breasts and a nicely trimmed bush. “You have a great body, detective Riley. And a sexually experienced one, I can tell it.”

She would like to keep silent, but the drug pulled her tongue. “Because I am! I’m attending sex parties, you know. Even BDSM ones. I love to be used!” She giggled.

He was surprised. “A policewoman and a sub ... Who would have thought. A perfect candidate for our cause, one might say. You won’t be resisting ... you will be embracing.”

The final shreds of her defiance crumbled. Embracing. That word resonated deep inside her, a bell struck in a cavern. She had always yearned for a release this total. In her controlled forays into BDSM, she had always kept a piece of herself back, the part that was a mother, a cop, the responsible one. Now, Sensyl was holding that piece in trust for her, whispering that it was safe to let it go completely.

Jack stepped aside and bowed towards a door hidden in the wall, which opened silently.

“Please. After you.” His voice was smooth as velvet, a courtesy that was far more terrifying than a threat.

Riley took a step forward, her bare feet silent on the cold concrete floor. The two thugs fell into step behind her, a silent, menacing escort. The hall beyond was long and sterile, illuminated by dim, cold, clinical light panels in the ceiling. This wasn’t the lair of a simple pervert. It looked more like a high-tech research facility.

He opened another door. “Be my guest. The today’s batch of the women is almost complete, two more, and we will begin. It won’t be a long wait.”


Riley stepped in, and the door closed behind her. She looked around curiously.

A low-ceiling, windowless, dimly lit, cool room. She began to get accustomed to the theme. No furniture, just several thin, worn mattresses on the floor.

And nine more naked women and girls, from about her age down to— fourteen, maybe? All of them clearly filled with Sensyl, just like her, their bodies moving with a loose, sensuous grace Riley recognized from drugged-up orgies. A faint, sweet smell of sexy juices in the air. Her body responded instantly, her own arousal intensifying, dampness spreading between her thighs. This was not the detached observation of a detective. This was the response of a body ready to join.

Some of the women were lazily touching themselves. Others were cuddling and whispering to each other, their voices soft. One young woman, maybe twenty-five, was looking at the girl sitting next to her who Riley estimated was only fourteen. The younger was nervously hugging her knees to her chest.

The woman extended a hand. “Hey. What’s your name?”

The girl looked up, her eyes huge and dazed. “ ... Sophie.”

“I’m Maya. Are you scared?” The girl nodded. “Don’t be,” Maya said, her voice a soothing balm. “I’ve heard. I saw the Changed girls. They say, this is the best thing you can ever experience. Better than Syl.” She paused. “Much, much better.”

A different kind of fear, pure and cold, pierced through Riley’s Sensyl-induced haze. She’s going to become Changed soon. She’s going to lose herself, forever, to turn into the always sex-craving female, like Lila, always focused at her pleasure. This thought, even through her high, felt like a shard of ice in her blood. But the fear was distant, muffled, like a scream heard through thick walls. Her body didn’t care. Her body was warm and ready. Her locket, containing Lila’s innocent face, was a cold weight against her heated skin. What would her daughter want for her? To escape? Or to finally join her in this new, hedonistic existence?

Maya noticed Riley watching them and smiled, her gaze sweeping over Riley’s athletic frame. “You’re new, too.”

Riley blinked, finding her voice again. “I ... yeah. Just arrived. Aren’t you, too? Aren’t we all new here?” Her own words slurred slightly, lazy and soft. The urge to join them, to feel their skin against hers, was becoming overwhelming. This was more than just Sensyl. This was the room itself, the atmosphere of shared, impending surrender.

Maya patted the empty spot on her mattress. “Come. Sit with us.”

Riley walked over, her movements feeling both clumsy and graceful in the drug’s grip. She sank onto the thin foam, the surface yielding beneath her. The scent of Maya’s skin was close, clean and warm. She felt the girl’s, Sophie, hands reaching for her hips, the Maya’s cool breasts touching her shoulder from another side...

“Well, I was the first one to get into this room about three hours ago,” Maya said, leaning toward Riley. “I had time to exchange gossip. I saw among my friends who I will become. Who we all will become.”

Their lips met. It was a soft, tentative kiss at first, but Syl made the contact bloom into a roaring fire of sensation. Sophie shifted behind her, her small hands tracing patterns on Riley’s back, her breath hot on her neck. This was a kind of intimacy Riley had rarely known, a seamless merging of bodies and desires without negotiations or boundaries. The professional observer in her screamed that this was strategic, a deliberate softening-up, but her body, her senses, didn’t care. This was heaven.

Riley remembered Lila, her radiant happiness, how she had told her, “Mommy, you’re always so tense. This ... this makes everything feel warm and simple.” Was this the ‘why’? Had Lila been waiting in this very room? Had she been held like this, exchanging touches between strangers, before she was Changed?

The thought should have been horrifying. It should have fueled a desperate escape. Instead, a wave of something complex washed over her—a horrifying, gut-wrenching envy. She wanted to understand her daughter’s joy completely, to inhabit it. To know for herself what this liberation truly felt like.

Riley pulled Sophie closer, the move she learned with their last months with Lila, and pushed her fingers between the girl’s legs, feeling her hot wetness. Sophie moaned softly. Riley felt Maya’s fingers finding her clit.

“Why don’t get some pleasure ahead of schedule?” Maya purred.

And two young women and one teen entangled together.


After what could have been ten minutes or an hour, and a dozen of mutual orgasms, they floated back into the reality, all sweating and breathing heavily. There were traces of blood on Sophia’s inner thighs, she’s lost her virginity, but she did not care.

Right after two more girls were brought into the room—they did not even had the time to sit down—another doors opened, and a man ordered them all to came in. They obeyed. It their present Sensyl-enhanced arousal, it all was just a teasing prelude to something much, much better.

Twelve mattresses were arranged in a half-circle on the floor, with short smooth posts rising from the floor on both sides.

The men led Riley to her spot and laid her on her back. Two posts protruded near her hips. Riley now saw that there was a row of bolt holes in them. They told her to raise her legs, pull her knees to her shoulders, and press her ankles outside the posts. She obeyed, and the men promptly screwed two horizontal bars onto the posts, one below her feet and one above. Finally, they handcuffed her wrists to the bottom of the posts. The other girls and women were fixed in the same way.

Riley admired the construction. Being a BDSM sub, she was tied down and bounded countless times, but she never saw such practical simplicity. She was now almost free and at the same time fully immobilized, in a way that felt very, very comfortable – and very ready to be used. She laid on her back, her legs spread obscenely and held up by the bars, a position of utter vulnerability, with all her holes exposed and available. She could still easily move her hips and body to adjust herself to any penetration. Too bad she will forget it all; she would like to bring the blueprints to a couple of dungeons she was visiting.

A cold dread battled a liquid fire in her veins, and the fire was winning. Her body knew this pose and craved it. She was prepared to be exploited. How would it be?

She stared up into the mirror ceiling and saw herself and others, an arrangement of female flesh ready to be ... processed. The other girls seemed rather excited and laughing nervously. Even young Sophie. Riley heard whispers, like she had from Maya. They all know what was coming. And they seemed okay with that. Happy, even.

The men left the room, closing the door after them. The silence fell.


Then several low-mounted doors, more like shutters, opened. With a sloshing, slithering sound ... something ... began to enter the room.

Riley gasped and opened her eyes wide. Sophie by her side sobbed and whined.

The things looked like giant, human-size slugs. They weren’t exactly slugs, they were more like blobs of goo, they protruded and retracted eyestalks and tentacles, helping themselves to the semi-circle of helpless girls. They moved slowly, but with deliberate precision that left no doubts about their destinations. Their skin—a semi-translucent, opalescent gelatin—seemed to ripple with a life of its own. And they smelled faintly of salt, iron, and something else, something organic and profoundly sexual. The scent that made Riley wet.

Fear, sharp and acrid, finally cut through her fading Sensyl haze. This wasn’t sex with a partner, willing or forced. This was something else entirely. Her mind recoiled, screaming about parasites, about alien biology, about the ultimate violation. This was a true monster, a thing of nightmares. She yanked at her cuffs, a futile, desperate motion.

A creature reached her first. Its eyestalks swiveled to fix on her, and she felt its attention like a physical touch, then they retracted. The creature did not need eyes anymore to find her. Another reached Sophie. Another, Maya. The girls around were gasping and crying. “No, no, please...”

Riley was trying to keep her mind clear. She had to observe. For her report. For Lila, who had experienced the same thing. Well, she was going to forget, like everyone else, but she still had her recorder working silently. Working, hopefully. And she still wanted to experience, to feel, to remember.

The creature moved over her. Its cool, gelatinous bulk settled onto her exposed abdomen and thighs, shocking her system with a clammy pressure. It was heavy, exactly the weight you’d expect from the body of this size. She whimpered, feeling the slimy touch to her whole bottom, to her feet, to her legs, to her ... most sensitive things. A quick glance at the ceiling showed herself, Sophie, Marie, all others in the same position, their lower halves covered with the throbbing goo. And it kept crawling higher.

As it slid over her mound, Riley braced herself, expecting a violation. But it paused, its surface seeming to vibrate in a low, resonant hum that traveled directly into her nerves, into her very bones. The vibration wasn’t mechanical. It was alive.

It moved further up, covering her belly, climbing towards her breasts. Her hardened nipples screamed as the soft, yielding flesh of the creature enveloped them, the vibration intensifying. A wave of liquid heat washed over her, so intense it bordered on pain. Her back arched as far as the restraints and the pressing weight would allow, a guttural moan tearing from her throat. Her mind, the detective’s mind, tried to catalogue it, to file it away as ‘evidence’, but her senses were being hijacked, rewritten. Oh God. Did Lila experienced the same violation? Yes. Of course. She did. And she came out changed.

Riley’s whole skin, covered by the creature, suddenly burned, as if thousands of thin needles penetrated her, releasing their load, just for a second. The hot shots at her vulva and anus were the most painful. Riley screamed and arched, and other girls echoed. She felt the hotness spreading over her whole body, fast, burning. For a split of a second, everything turned into a white, empty void. Then the feeling faded.

She lay limp and breathed heavily. Her skin tingled all over. The previous pain was replaced by a deep, thrumming warmth. The creature on her chest contracted slightly, crawling up and squeezing her breasts. It wrapped around her arms, shoulders, and neck, flowing under her back and engulfing her head. It touched her face. Riley moaned in terror, fearing she would suffocate, but the goo left her nostrils and eyes open. Only them.

She floated, wrapped, embraced by the goo, tighter than any man could hug her, more intimate than any hot bath could reach. She could not help but moan with the pleasure— and impatience. She wanted more! Her throbbing, hot, twitching body wanted more! MORE!

And then it happened.

She watched through the ceiling mirror—her last act as Detective Riley Morgan—as what looked like long, pulsating tubes, tentacles as thick as her own arm, began to form within the creature’s translucent main body. They was slick, segmented like an earthworm, with rounded, blind tips that probed the way. There were three of them, and they extended slowly, with a horrifying, biological purposefulness. Two headed for her inviting crotch, and one targeted her forcefully opened mouth.

She understood its purpose with a crystalline, horrifying clarity. This was it. This was the Change.

The lower one pressed against her already soaked and stretched folds, not asking permission but simply asserting its will. The pressure was immense, insistent. She tried to clench, a final, futile act of defiance from muscles that now existed for another purpose. But it was like trying to stop a tide with a handful of sand. Her body yielded, the tendril pushing inside her, stretching her, filling her beyond any capacity she thought she had. There was almost no pain, only the stretching and filling she never felt before. There was only a sudden, overwhelming completeness. A shudder wracked her, a full-body spasm of pure pleasure, as it pushed through her cervix and began filling her womb.

The second lower tendril circled her anus before pressing, slick and insistent. The entrance was tighter, a small rebellion of her nervous system. But her body, rewired by that initial hot injection, betrayed her. Her muscles relaxed, welcoming the invasion. As it slid home, nestling alongside its twin in her passage, a second, deeper level of existence opened up within her. A feeling of being so utterly, profoundly filled that it erased all other thoughts. The police precinct, the case file, her daughter’s worried face—it all dissolved in the feeling of urgent, insistent, stretching violation. Deeper and deeper into her body. And ... she welcomed it.

The last tendril stretched her lips and pushed her jaw even wider. Riley barely managed to let out a muffled moan before the tendril pushed into her throat. Again, there was no gag reflex, only an easy yielding and a sensation of being completely and irrevocably used. No pain. Only the deep contentment of submission and losing the last bits of her agency remained. From what she could tell, the tendril had reached her stomach.

She hung for a moment, enjoying the hot slimy embrace, the stretching, the fullness, the completion.

Then the tendrils began to move. Slowly and cautiously at first, then they gained the rhythm and range that Riley knew all so well. The thrusts of horny and impatient men with big dicks. Only now she felt them within her whole body, as deep as no man could reach. The big pulsating thing on her chest kept vibrating all the while, squeezing her breasts, pinching her nipples and the skin everywhere, from neck to armpits to bare soles, amplifying her arousal beyond what she thought could be possible.

The room was filled with the sloshing sounds and muffled short moans.

 
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