Byleth hears the girls out.

The professor standing in the doorway was the enigmatic Byleth, a woman hand-chosen from the famous Jeralt's Mercenaries by the Archbishop herself to teach classes at the Academy. She'd proven her mettle by rescuing the three House leaders when they were attacked by bandits some months ago. Although, when given the choice, she'd chosen to teach the Blue Lions and not the Black Eagles, her mysterious nature and outsider perspective often made her a target of interest as either a puzzle to solve or a sounding board for problems. As a result, she was on a friendly basis with many students at the academy, even those outside the Blue Lions.

Another obvious reason people wanted to be around her was her looks. The black coat the professor wore was the only thing that really gave her the appearance of her title. Otherwise, her outfit was a mess of motifs and was considerably flashier than most students' uniforms. A black corset, short shorts, and tall boots, together with ornate sheer stockings, joined metal pauldrons, gauntlets, and greaves that spoke to her previous life as a mercenary. These imagination-stirring details were secondary still to the blue-haired beauty's knockout body, leading some students to refer to her as the Academy's "Goddess" (never to her face or within earshot of a church official, of course).

The young adult ordinarily at the center of all that attention didn't seek it out: truth be told, every day was a struggle for her to get used to life as a teacher after formerly living as a mercenary with no past. Still, Jeralt had taught her a thing or two about how a leader ought to appear before those she meant to lead, and she tried to carry that demeanor throughout her teaching days.

Byleth's cool blue eyes locked with Bernadetta's for a moment, then shot down to Edelgard's still-bouncing ass just below her Bernadetta's chin. Finally, Byleth glanced away and cleared her throat. "I'm going to close your door."

"S-sure!" Bernadetta coughed, before Edelgard poked her aggressively in the foot. "Eeehehe! I mean, n-no, don't! Something really bad is gonna happen if you reach in here for the handle!"

The Professor's momentarily glared at Bernadetta's perceived threat. When the young girl flinched in terror, Byleth realized she must have been mistaken. She gave it a second thought and came to another conclusion. "Is someone threatening you two? You and... who?"

"Oh, um, th-this is Lady Edelgard," Bernadetta helpfully offered. "You know her, right, Professor?"

Edelgard let out a muffled groan into the pillow. "Thank you for that, Bernadetta..."

Byleth nodded, although her eyebrows raised. "That's unexpected."

Edelgard decided to speak up, turning her eyes to the doorway while still hiding as much of her face as possible behind her shoulder. She positioned herself on her knees against the headboard of the bead, pushing her butt against Bernadetta's as the other woman remained face down. "I'm sure it isn't as surprising for you as it is for me... Professor, there's an explanation for what's happening, but I have no time to give it. Bernadetta and I need your help, urgently. There's music coming from next door that's causing this. Since your class is involved, I'd appreciate you taking responsibility. However, you must promise two things."

The teacher stared at the two students bumping their butts together to an unheard rhythm, thinking this was an incredible position to demand anything from. "I'll hear you out."

Edelgard raised a hand in the air, finally regaining a dignified, commanding expression. "First, you must promise not to listen to the music. Cover your ears in some fashion. If you were to hear the music, you would become filled with the same irresistible desire to dance as Bernadetta and I."

"Among other desires, it seems," Byleth commented.

"Second!" Edelgard called testily. "You must promise not to tell anyone of this, please. Needless to say, the moment you free us from this curse, Bernadetta and I will once again return to being responsible members of the respectable Black Eagle House and go our separate ways for the night."

"I see." The teacher nodded. She paused with a distracted look, as though listening to someone else. If there was another voice to hear, it wasn't caught by either of the two dancers on the bed. Quickly, Byleth was present again. She gave them a nod and the faintest of smirks. "I understand. I'll be right back. Don't have too much fun."

Edelgard was still holding two fingers up for no apparent reason as she bucked her own hips against Bernadetta's backside. "This has everything to do with magic and nothing to do with pleasure. You promised to understand that, Professor, so see that you honor that promise." As she finished speaking, trying to keep a stern gaze on the Professor to show that she was serious, she found herself bringing the held fingers towards her mouth and lewdly licking between the V they formed with her rarely-seen tongue.

In spite of that, Byleth gave her an all-business nod, then left the doorframe.

Bernadetta whimpered. "She wasn't able to close the door after all, huh? I hope she comes back soon! Don't you want to dance with the Professor, Lady Edelgard? I wonder if she's really good at it... Don't you wanna see?!"

The Adrestian noble seemed to be giving it unusual consideration, still wagging her tongue before she came back to her senses. "The Professor is going to turn off that music and free us, Bernadetta. If she comes back without doing that first, I don't care to see her."

Byleth remained paused outside the door to Annette's room, standing a safe distance away. She knew it was safe because she hadn't started motoring her butt like the two Black Eagles she'd just left. She clapped her hands over her ears in an attempt to guard against the sound. Then, she tried vocalizing a bit to herself, emitting a dull hum like warming up for choir practice in her usual emotionless voice. She frowned, disappointed to find she could still hear her own voice. "This isn't going to work," she spoke in her head.

"Naturally not," another voice spoke in her head, in an arrogant tone and a dialect long lost to Fodlan. Her father figure Jeralt's advice wasn't the only thing that kept Byleth out of trouble: sometimes, that honor belonged to this mysterious voice that had one day awoken and begun to speak to her inside her own head. Sometimes, it even spoke more directly in dreams. In those dreams, the voice belonged to Sothis, a short, green-haired woman in an ornate gown with an unknown connection to Byleth. "Fool, have I not already told you of my premonition? You are about to face a power beyond my comprehension. If it is beyond my comprehension, it is surely far beyond yours!"

"You said that, but I have to try."

"Yes, yes, do I not know it!" Sothis complained. "As ever, depend on my power to rescue you from peril you put yourself into. As of now, your choices are but your own."

"... I'll knock. From outside, I'll ask them to turn it down."

"... The diplomatic approach, is it? Befitting of one granted authority as a teacher. Very well."

Clapping her gloved hands over her ears, the teacher approached her students' door, bracing herself. She wasn't sure what to expect. Would she find an evil, cackling mage, someone like the people who had replaced Monica before the Black Eagles came to her rescue months ago? Or would she find Annette herself, teary-eyed and wiggling her tiny bottom helplessly in her underwear? The same noise prevention that was helpfully keeping Byleth from hearing the faint thrum beyond the door was also keeping her from recognizing giggling voices inside, which might have helped inform her guess.

Still covering her ears, the Professor repeatedly rapped her armored knee against the door. For a while, she was standing there, waiting for an answer. Finally, as it began to open, she bent her shapely legs, preparing to leap back at the first sign of danger. After all, there'd be no way to wield the knife she carried in close range and avoid hearing the music. She was no slouch in the magic arts, though, and she intended to defend herself if a stranger opened the door.

However, no amount of preparation, neither her combat experience nor even seeing two students in their underwear earlier that night, could quite prepare her for what greeted her.