Byleth's rescue takes a couple of tries.

The door swung open to reveal Annette in her underwear. That was the first and last part of what it revealed that was within Byleth's expectations.

The short student standing there looked mildly surprised to see Byleth standing in her doorway, but she hadn't shown any reservations in opening the door for her. In fact, she looked remarkably calm, even chipper, for a captive of body-controlling magic. Annette had her hair down and wore a pretty, powder blue bra and panty set. The harder Byleth looked at Annette, however, the more of a stranger she seemed. If the Professor had to pick words to describe this student, "studious," "goofy," "childish," or "sweet" would ordinarily come to mind. As if she'd shed that image along with her clothes, both the bra and the panties this Annette wore had thin straps and dynamic angles, showing off hips and cleavage that left Byleth rubbing her eyes. The chest could have been bound, and the hips had been hidden by a skirt, but the legs were definitely thicker than the teacher had seen before. Was this some kind of impostor, after all?

Annette looked from Byleth to the room behind her, nodding at someone. That someone approached the door, and when she came into view, Byleth's shock grew even greater. Mercedes, a woman who normally gave off an angelic or sugary-sweet impression, was also dressed in nothing but remarkably skimpy underwear. The gold bra and panty with decorative frill had a glossy sheen and looked more like a swimsuit to Byleth than undergaments. The relatively open bra gave an eyeful of cleavage, and if Mercedes was turned around, the Professor imagined she'd be getting a peek at butt cleavage, too. Mercedes definitely didn't have the fittest body, considering she exercised less and ate more sweets than the average Academy student, but the slightly chubby curves pinched by her garments had a different appeal. She didn't look shocked, either, but unlike her friend, she did have some color in her cheeks. Byleth lipread her saying "Professor..."

Even standing there, both students were idly shaking their hips. It was a sight that left the teacher, who still found drawing appropriate lines between herself as an authority figure and her students (nearly her same age), a bit flustered. By the time she had parted her lips to begin making demands, the Blue Lions had already shared another glance and nodded without speaking.

Byleth didn't have a chance to begin. Before she could, each woman had snapped their hands out to grab one of the teacher's arms, then dragged her from the entrance and into the already crowded dormitory room.

She began to protest, but it was too late for that. Annette and Mercedes hadn't just pulled Byleth into the room: they'd pulled her shielding hands away from her ears. Before she knew it, Byleth's ears were being assaulted by the irresistible dance beat blasting from the gaudy golden box on Annette's dresser. Gritting her teeth, the teacher was able to easily yank her arms free from her relatively wimpy students, but when she raised her hands to place them over her ears, she found them crossed behind her head instead. Understanding she was already caught, the teacher couldn't help but growl in frustration as she found herself squat low, rocking the booty in her black shorts against her will.

Now that she was inside and thought she'd seen everything, Byleth was only mildly surprised to see Ingrid was here as well. The ordinarily straight-laced blonde was wearing a more conservative pair of tight grey shorts and a light shirt, but the high-arching peaks of dark blue straps at her waist seemed to suggest whatever was below that might be eyebrow-raising. More importantly, Byleth was certain that the handfuls pushing against that shirt was more than the modest chest Ingrid's lithe body had before. She approached Byleth with a concerned frown. "She doesn't seem pleased..."

"I'm not," Byleth responded sharply. "Also, don't talk about me like I'm an animal you caught."

"I didn't like it at first, either. Trust me, Professor, you'll love it if you give it a try. Oh, also, you've arrived just in time to judge our contest! Finally, we'll have a third party to-"

Mercedes was still watching Byleth with quiet interest, but she interrupted Ingrid's enthusiastic declaration. "Now, now, Ingrid. The Professor probably has questions."

Annette leaned against Mercedes' side and waved her off. "Questions can wait. This party's about dancing!" She gave Byleth a strange, catty smile. "I think you're a natural, Professor, but you might find it a little hard to keep up dressed like that. You can make yourself more comfortable if you want. You're among friends, and we're all girls here!"

Byleth didn't respond with words. What she did, instead, was take a seat in the chair no one was using, prop one of her feet up on Annette's desk, and show off her hose-clad leg while removing the boots and armor on her legs. Her face was the only part of her that remained defiant, as the rest of her seemed ready to join the party. She rose to stand in her bare feet on the wooden chair, wasting no time shrugging her dark coat off with shimmying shoulder jerks and waving her hips for her students.

Ingrid and Mercedes seemed to believe they were seeing something incredible, both watching with wide eyes. Annette alone was vocally egging her teacher on, doing her best to shoulder the party atmosphere. Regardless of how they felt about it, all three students still swayed their own hips in time to match the professor's.

Feeling her face hot with rare emotion, Byleth began to unfasten the belt that also acted as her dagger holster. She tried to think of some way out of this. She wanted to speak to Sothis about it, but any voice in her head seemed powerless to speak over the music that had invaded her ears and brain. "There are consequences to what you're doing," she managed to speak, a threat made unconvincing by the way she was beginning to slide her own shorts down her impressive hips and stick her butt out for the girls she was threatening. She heard Mercedes make a strange sound, like a gasp or a coo.

Byleth was surprised to hear Ingrid speak up. "That has to be wrong, Professor. You're not doing anything you don't want to, are you? To a one, each of us does what the Boom Box commands because we want to. Surely there's not any consequences for doing what you, yourself, want to?"

"Right!" Annette agreed, nodding fervently. "And I don't think anybody can be held responsible for what they want to do while the music's playing. Like if the three of us want to feast our eyes on our Professor's gorgeous body... or if our Professor wants to get an eyeful of her cute, compliant students... Nobody can judge us when the Box is making us want it!"

"We... can do whatever we want, and no one can judge us? Is that right?" Mercedes seemed to pose the question to Byleth while keeping her eyes focused on the dark, mature panties beneath the pantyhose her teacher had just revealed and begun swiveling.

Byleth saw something strange in Mercedes' eyes and coughed, trying to think of what to say. "That's not-"

Either not hearing her or otherwise ignoring her, Mercedes approached with a small, excited smile and, to everyone's surprise, pressed her cheek to the side of Byleth's hips, beginning to fondle the other woman's legs as she wiggled her own hips to the beat. "Oh, dear! I can hardly believe the music is forcing me to play with your lovely body, Professor. I've certainly never dreamed of doing anything like this when you walk by with those teeny-tiny shorts in class, hm hm hmm...~" Hearing no one join in, Mercedes looked around the room. Even Annette looked shocked. The blonde reddened deeply, although she didn't stop snuggling her teacher's hip. "Ah, um... th-the music even makes us say some bizarre things sometimes, doesn't it?"

"N-no, not at all!" Annete told her friend, trying to reassure her. "The Professor has an incredible body and wears such a sexy outfit, it's just normal you'd feel that way with the music exciting you."

Byleth watched her students with a frustrated scowl. "Do you all really feel that way about my clothes?"

Ingrid's eyebrows lowered. "That's what's bothering you, Professor...? Never mind. As an educator, you're free to wear what you want. I think most of us are quite used to it. Anyway, Mercedes, let's give our poor Professor's dignity a break. After all, I think it's high time we had our competition judged!"

Feeling like she was in a dream, Byleth let herself be led to Annette's bed and perched on it with her chest down and her ass waving in the air, facing her impassive glare to the room while her students took turns dancing for her. She saw Annette skillfully step with the beat and playfully shake her hips, winking her big blue eyes and sticking her tongue out. She saw Mercedes dip low and quake her frankly massive ass, the curious student's face burning with a variety of excited emotions as she felt her teacher's eyes locked on her lower body. She saw Ingrid putting her all into an energetic dance, her usual confidence wavering in a shaky, unsure smile as she peeled her shorts down slightly to give Byleth half a peek at the hinted thong she wore.

And as the feverish dancing continued, Byleth had to admit to herself... What strong attachment did she have to the idea of herself as an authority figure? It didn't seem so heavy that she couldn't set it aside. If there was a power imbalance here, it was against her, not for her. If she separated herself from her role as a teacher and looked at things objectively, things popped into her head that she could never have imagined admitting to herself.

Dancing was... actually fun! Her students... were quite attractive! And she, herself, was rather horny-

As if crossing that line in her mind had triggered it, Byleth suddenly found space warping around her. The party she was enjoying seemed to shift so she was viewing it from outside... It was no longer even the same room, but the room next to it. Byleth was fully clothed again, on her feet, and perfectly still, staring at Bernadetta and Edelgard showing off on Bernadetta's bed. Edelgard was facing Byleth with a strange but now familiar gesture, wagging her tongue through the V of her fingers while wearing a stern frown.

Byleth staggered drunkenly out of the doorway and towards the room next door, leaving the two Black Eagles girls with an uneasy feeling.

When she was out of sight of them, she shut her eyes and spoke in her head. "Was that your Divine Pulse?"

"Indeed," Sothis' voice responded. She had her usual haughtiness, but even she sounded a little shaken by what she'd witnessed. "It matters not how you have fun on your own terms, but, as I feared, you fell to the snare of potent magic. You are surprisingly **** to invasion by outside influence...! As I am joined to your consciousness, that outcome is not acceptable. For you to lose control of your body is not unlike losing control of my own! The humiliation cannot stand! By the by, are you aware of the effort required to bring my power to bear whilst you are not in mortal danger?! It is most strenuous! I advise against testing it again."

Byleth crossed her arms. Her face looked nonplussed, but Sothis could tell she was in a bad mood. "I have to do something."

Sothis joined her in pensive silence for a moment. "Indeed... Your students displayed a boldness of character and vulgarity of form suggesting a corrupting outside influence. If left alone, it is not difficult to imagine far-reaching consequences. However... a thought occurs. A way by which your aim might be achieved. I do not believe you will accept it happily, and neither do I happily offer it. Are you determined to save your students at any cost?"

"Yes," Byleth responded without hesitation.

"Very well..."

None of the girls in Annette's room were prepared when the door suddenly flung open. Ingrid, who had been upside down against the wall in the middle of an animated performance, fell over in surprise and was **** to untangle her own blonde braid from around her face.

Byleth was standing there, but not as any of the three had seen her. The woman's ordinary cool blue hair and eyes had become a bright, otherworldly shade of green, and no clear emotion displayed on her face. In contrast to her three students, the woman stood perfectly still, as though ignoring the music entirely.

"... P-Professor?" Annette greeted her with a sheepish grin. "We're not in trouble, are we? This Box is, uh..."

The young woman's words trailed off as she realized her explanation was falling on deaf ears. In a way that seemed not entirely human, Byleth strode into the room and grabbed the box. She carried it to Annette and thrust it in front of her. "How do you disable this infernal device?" Byleth asked in a strange, booming voice.

Annette didn't answer, but Mercedes did, sounding slightly proud of the knowledge. "I believe it's the lever with two bars, Professor. It's a bit tricky to figure-"

Realizing what was happening, Annette and Ingrid both rushed to grab the Box Byleth was now holding. The way they were holding it, they probably intended to put up a struggle to keep it from being taken away. As soon as Byleth pressed the button Mercedes had told her about, however, their grips went slack, allowing her to tear the Box from them, briskly turn, and march out of the room with no further explanation.

The three students stared at the door, dumbfounded. Ingrid gulped, then said what all three of them were thinking. "I fear we're in trouble."

Back outside, Byleth felt her strength leave her as her hair and eyes returned to their regular colors. She saw the door to Bernadetta's room was already closed and assumed the two inside, free from the influence of the box, had finally hidden themselves. As she headed shakily towards her own quarters at the other end of the dorm, she searched for Sothis in her mind. "It worked."

To her surprise, Sothis took a long pause to respond. She sounded as exhausted as Byleth felt. "Yes... Naturally. If I say it shall be done, you should never doubt it. Although the circumstances were... most incredible."

"Thank you." Byleth made it to her own room and stepped inside... Immediately, she grabbed her sword from the scabbard hanging on her wall. "I'll destroy it now-"

"Stop!!" Sothis' voice was so loud in Byleth's head that it almost made her ears ring. "That is... I should say, do not be so hasty, fool! Did I not say this artifact is beyond your comprehension? Any attempt to destroy it could well be our undoing, and this time, I would be unable to rescue you. No, you would be wise to leave this to me once more. I have an idea that may prove most amusing."

"... Amusing?" Byleth asked.

"Ah, did I say amusing? I meant, um... wise! Beneficial to our well-being," Sothis corrected herself.

Byleth was concerned, but it was too late to worry about it further. In the end, leaving it to Sothis had definitely been the right call earlier that night. She owed her mysterious partner the benefit of the doubt. "Whatever your plan is, can it wait until morning?"

"Indeed... Rest well. I shall not visit your dreams tonight. I must recollect... how to draw something. It concerns you little until morning arrives."

The Professor didn't respond to that. Her gratitude for Sothis' help would be not to question it.