A grand unveiling to the court

On the day that you would finally take the place you had wanted for so long, your sister wakes you in the early hours of the morning - long before the sun would come up. You don't bother to dress as you follow her out of your chambers. You walk through the palace halls, nude as the day you were born and with only the moonlight lighting your way. No one sees you; no one else is awake at this hour. The idea that someone could is thrilling, of course, but it would rather spoil the plan.

Your destination is one of the antechambers off of the throne room. Sometimes these rooms are used as waiting areas for visitors or supplicants. In other cases, such as this one, they are where a royal would keep items or persons that they wished to unveil to the court at an appropriate moment during the session. You know that your sister has been having something built here for you and your unveiling, but the precise nature of it has been kept from you by mutual agreement. A surprise gift for you.

When you enter the room your gaze quickly lands on a box situated in the center of it. It will certainly contain your restraints, but right now you can only make out some breathing holes and seams - whatever is inside it is as yet a mystery. You long to open it and see, but Cecilia first catches your wrist and pulls you to a side table with the last few potions you need to take to complete your transformation.

First a potion that will prevent you from getting with child - ordinarily it would wear off with time, but your sister tells you that in your case certain enchantments on your restraints will interact with it in a way that will allow it to both last in perpetuity and be selectively turned off for special cases. With it went various potions that ensured you would neither catch nor transmit diseases. Next you swallowed a peppermint-flavored concoction that will boost your libido and wipe away your refractory period. Moments after you finish it you feel a heat coiling within your gut, and only will and the knowledge of coming satisfaction keep your hands from straying to self-pleasure. The efforts are not helped by the potion after that, which increases your sensitivity - a draft in the room is enough to make you shiver with want.

And the final potion, the most expensive to procure and make. You had thought it a passing whim, but sheer fortune saw it fall into your lap - a potion to suspend aging and bodily degradation indefinitely. Immortality. In theory any would want it and it would have a better use than this, but not only was it expensive and difficult to truly make - and therefore obtain - it also made the drinker highly suggestible, such that any ambitious ruler who aimed to take it would immediately put themselves at tremendous risk of becoming little more than a puppet when any discovered what they had done. Of course, you weren't aiming to remain a ruler.

When the last potion you needed to drink was downed, your sister at last moved to the box. She flicked open a few latches around the side of it before pulling it open such that it laid flat on the floor. Inside was a framework of chains, bands, and bars, clearly sized to hold you nearly perfectly still in place. Currently it would hold you kneeling and bent forwards, your pussy and ass exposed while your upper half was thrust forwards and your hands were held stretched up and behind you, but you could also see it was built such that another person could change and vary your position in numerous ways. You couldn't tell what all the possibilities were at a look, but - you thought with a thrill - you would begin to find out soon enough. You also saw various other implements clearly meant to be buried within you when you weren't in use.

As you took all that in your sister had opened all the shackles and bindings, and now she gestured for you to come over to her. You did so eagerly, excitedly, kneeling in the shackles that would line your legs and moving to let your sister seal them closed. Next went a band just above your waist, forcing you into the bent-forward position. Then she shackled your left arm in place, one band at the wrist and another on your bicep, and paused. You looked at her in confusion, which caused her to sigh and drag your right arm away from where it had started working at your soaked cunt. You hadn't even noticed you were doing that, but you felt the loss of stimulation keenly. Your sister put clamps on your nipples, which briefly interrupted the whine building in your throat with a yelp.

The last binding you'll be wearing is a collar, etched in silver and gold - as is much of the frame. Your sister took it in hand, positioning it around your neck. You looked each other in the eyes, one last time. "Enjoy yourself, Anne," your sister said.

You smiled through the pink haze that'd descended upon you and replied, "Thank you, Cecilia." It's likely the last time either of you will refer to the other with the names you were born with.

Your sister closed the collar around your neck with a click. It sealed shut; there is no way to remove it now. Then your sister rebuilt the box around you, plunging you into a darkness broken only by the light that spills through the air holes. You heard the latches flick closed, footsteps walking away, a door open and close. And just like that, your sister is no longer a maid but a queen, and you are no queen but instead a whorish sex toy left to stew in her lusts. And indeed, the loss of sight and sound leaves you with little to focus on beyond your now ever-present arousal.