The night was calm and quiet. Countless stars drew pictures and stories into the sky, for those who could read them. The full moon cast a dim light over the garden and walls of the old Greychant Manor. The building had been home to a powerful family of mages and spellcasters before being turned into a boarding school for a small class of promising students, by the most recent family head, Sivillia Greychant.
The students treated their strict but motherly teacher with respect and none of them would have ever wasted a single thought to breaking the rules and using their skills in unsightly or depraved ways. Or most of them wouldn't. The rest would simply hope not to get caught.
Not all residents of Greychant Manor were asleep that night. The light of a single flashlight danced in the hallway. The flashlight belonged to Amelia, one of Miss Sivillia's chosen students. Quietly, taking a quick glance over her shoulder at every turn, she hurried back to her room from the expansive library. With her free arm, she held a book pressed to her chest. She was almost to the corridor that led to the girls' rooms when quiet steps reached her ears.
Quickly, Amelia turned off the flashlight and pressed herself to the wall, into the shadows, away from the moonlight that swept in from the windows. As the steps came closer, a blonde girl turned the corner, her pink nightgown and white socks breaking the darkness. She shuffled with her eyes closed, her arm stretched forwards lazily, in the vague direction of the toilets. Amelia held her breath and pressed a hand to her own mouth as the other student wandered past her. She only released her breath after she heard the bathroom door fall shut.
Her heart beat fast in her chest. Sneaking out past the curfew at night was already exciting in itself, but what was about to follow was all the more worth it. Quickly, Amelia hurried back to her room and locked the door from the inside.

The lamp, over which Amelia had spread a thin, red cloth to dim the light, illuminated the room just enough for the student to read, but not too much as to not ruin the atmosphere. The book lay on her bed, opened on a specific page. Two objects, which she usually kept hidden away, lay next to it.
She quickly glanced at the clock before she started to undress. She had all night to finally put her plan into motion. Every night for the past week she had sneaked out to get the book and work on her tool, just to hastily return it every morning, in order to avoid Miss Sivillia noticing that it had gone missing.
But all the preparations were finally complete and she could begin. This was the night she had been waiting for.
Standing in front of her mirror, she examined herself. She had a slender but relatively short body with medium-sized breasts. Her curly hair was as black as a Raven's feather and styled in a loose up-do. Green eyes looked back at her from behind red-framed glasses. Having gotten rid of her other clothes, she was now dressed in only a pair of white panties and a black undershirt, small enough to show her belly button.
Just imaging what she was about to do made her want to start touching herself, but as soon as she would start with that, she would just keep wasting time. She had to concentrate and cut to the chase!
Turning to her bed, she knelt down to take a look at the items placed on her sheets. First was the book, Bindings and Seals - A Collection of Spells and Chants, opened on a page reading Brace of Binding. Next to it, there was a leather collar with a silver buckle. It was a quite common accessory, at least at first glance. It indeed used to be, but these past nights Amelia had spent hours enchanting it per the book's instructions, getting her sleep during the day instead, sacrificing her free time for this cause.
Next to the enchanted collar lay a roll of duct tape. It was normal tape, not enchanted in any way. It would do it's job the way it was, together with the black cloth next to it.
After going through all the steps again to be safe, Amelia carefully set the book aside and climbed onto her bed. Taking off her glasses and setting them down on the nightstand, next to the open book, she reached for the cloth. Balling it up, she pushed it into her mouth, making sure everything went in. Tearing off a strip of tape, she slowly and carefully placed it over her mouth and sealed it shut. She had already tested the effectiveness of this gag before and found it to be satisfying.
With care, as if she was balancing a fragile vase on her fingertips, she lifted the collar and looked at it for a moment, mentally steeling herself for the next step. Carefully, she opened the buckle, put the leather around her neck and closed it over her throat. She took a breath through her nose. It didn't feel any different from before the treatment, but she was sure she had done everything correctly. It would work.
Standing up, Amelia closed her eyes and relaxed her body, breathing deeply. She reached for her inner magic, as she had done many times before and began to forge it. With a slight push, she led it into the object around her neck.
That was all the command the collar needed.
Immediately, it forced itself tighter around her skin, pressing into it, though not obstructing her breathing. Amelia gasped slightly into the gag. Something cold ran down her body and when she opened her eyes - and squinted to see her reflection in the mirror - she saw thin silver chains flowing from the enchanted leather like droplets of water, wrapping themselves above, below and between her breasts, pulling her arms tightly against her body and extending all the way down between her legs.
A silenced yelp remained unheard as a single chain crawled over her panties, running between her legs to travel up her back. She had wanted to reach for it to stop it, but the chains around her torso parted and snapped around her forearms with a strong grip, violently pulling them behind her back and wrapping around them.
This was what she had wanted, what she had aimed for, and yet, a small panic overcame the dark-haired girl as the bindings forced her, digging into her skin. She began struggling instinctively, but the violent chains just pulled themselves tighter around her delicate body. They wrapped around her legs, pulling them together, making her loose her balance as she was thrashing around, falling backwards onto her bed.
Finally, only mere moments after being fed with her magic, the chains stopped. Amelia took a few deep breaths, clearing her mind of the shock. She knew how the enchantments were supposed to work, in theory, but actually experiencing it was a whole different thing. She hadn't imagined the spell to work so harshly. Her body ached but beside that, she felt a much more desirable thing: arousal.
Lying down on her side and lifting her strictly bound legs up onto the bed, she tested the bonds, trying to pull her limbs apart. The thin chains proved to be powerful shackles, not allowing more than a bit of wiggling. They subtly tightened, pressing into her skin before letting off a bit again.
The feeling of her bindings pressing into her skin caused the student to moan into her secure gag. She could clearly feel herself getting wet and her nipples hardening, the fabric of her shirt stretching over them.
Closing her eyes, she let her imagination wander. She pretended to see her kidnapper standing over her, a young woman with short hair, her cold eyes staring down at her lustfully. She had often invited this person into her fantasies, but never had she been feeling so helpless and at her mercy. She wouldn't be free any time soon and until she was let go - if at all! - she would have to endure much spanking at groping by her hands.
Getting into the mindset, Amelia started struggling. She wanted to escape, to get away! But the chains were relentless. They tightened around her body, around her breasts and as the chain in her crotch tightened, she moaned so loud, she feared someone might have heard her, despite the gag.
But the thought didn't last, the pleasure started to build. Moving her hips, Amelia attempted to grind against the chain, only giving it reason to pull tighter. This time, it even hurt a bit, but that only edged her on more. She kept struggling and wiggling as if there was a way to somehow break the chains and escape her imaginary captor.
Suddenly, she felt a pull on her ankles as the chains moved. Her legs were bent forcibly until the bindings on her ankles and wrists touched and perfectly merged into one. Amelia gasped and took another deep breath, caught off guard once again.
Her body started to ache, her mouth was drying up and she grew all the more desperate to race towards the climax. Reaching with her hands she quickly found the chain running up her back and pulled, digging it deeper into her crotch. The chain, in response, tightened and loosened again shortly after, as punishment for a possible attempt to escape. Moaning, the girl repeated the process, making the chain, dig into her crotch again and again, her breathing becoming faster and faster, her struggling becoming more desperate, but all the more meaningless.
Just a little more!, she yelled at herself, Come on! Come on!
Then, finally, the orgasm washed over her. She bucked and squirmed as she screamed into the gag, that did a marvellous job at still keeping her unheard.
The best orgasm of her life so far started to fade out, leaving a strictly chained and heavily breathing girl behind to recover. She lay still and took deep breaths. She wanted the gag to come off, wanted to move again, wanted to get up and take a shower. So, after gathering her strength, which took a few minutes, she began to pull her magic back from the collar.
Except she couldn't.
A feeling of dread overcame her. The collar didn't just restrict her body, it had effectively rendered her unable to call up her magic. The chains lay heavy on her delicate, aching body. Surely she had bruises from the harsh treatment.
Okay, calm down. The book.
She looked over to the nightstand. The book was still opened on the same page and was placed directly next to the dimmed lamp. Carefully and slowly, she started to edge over to it, the chains subtly tightening with every move, tightening around her limbs, her torso, her breasts, digging into her crotch. What had earlier extracted a lustful moan now earned a scared whimper instead. With will and effort, Amelia made it to the book and stretched her upper body as much as she could and squinted to be able to read without her glasses. Slowly, the words made sense to her. At the lower right corner, the final part of the description read:

In order to release the captive, temporarily or ultimately, a vocal command from the brace's master is needed. In order to disencha--

A vocal command. Amelia felt her eyes watering. Why had she not read that part earlier, how could she miss such a vital flaw!?
"Mmehiefh!", she tried, but nothing happened.
"Mmehiefh! Pwhs!" Again, no reaction.
Blinking away the tears, she attempted to read the rest of the paragraph to maybe find some kind of emergency method, but all she found was a hand-written note at the bottom of the page:

I know you are reading this book, Amelia. If you do not confess by the end of the week, I will have to assume that you are attempting to break the rules by secretly studying forbidden spells. Come to my office.
-- Sivillia

And just below a more recent one:

Since you elected to ignore my warning, I allowed myself to inspect your work. Admittedly, I am impressed by your skill, but deeply disappointed in how you choose to use it. I am sure you have rushed this page the first time and have now already experienced the subtle changes I made by now. I will come get you in the morning. Consider whatever displeasure you find in your predicament the first part of your punishment.
-- Sivillia