Immediately, Matti felt tears welling up behind her glasses, her backside throbbing to remind her anew of her last spanking, not that long ago at all. "No!" she sniffled, sure that's what was in store for her. "Pl-Please!"

But Ms. Emily didn't stop, or even slow, just kept marching forward, opening one of the doors Matti had been certain she'd checked and found locked. For Ms. Emily, it opened no problem, without a key or anything. The room inside immediately made Matti think of a principal's office, with a huge desk and a large, comfortable looking chair on one side of it, and a much smaller, unpadded, wooden chair on the other. The only differences she could see right away was the changing table on one side of the room, in front of a wall of shelves, stocked with what looked to be an almost endless supply of diapers of all different colors and designs, and a chalkboard on the other, which wasn't out of place in a school, though she doubted many principals felt the need to have them in their office.

Even with her fear of what was about to happen, Matti couldn't help gawking, her jaw open wide, as she stared at the huge variety. Ms. Emily chuckled, her grip loosening as she shut the door. "Why don't you go ahead and choose what diaper you'll go into after your change?"

"R-Really?" Matti took a couple clumsy steps forward. There were diapers with baby blocks, with bunnies, with trains, with ballerinas, with dinosaurs... Anything she could imagine was there, and more! She recognized a lot of them from her brief deep dive into AB/DL diapers online, but there were far more that she didn't. Of course, if this was an Interdimensional Daycare, as the name declared, the diapers could come from anywhere, too, surely.

"That's right, Mathilda," Ms. Emily told her. "I can put you into any one of those that you want."

What did she want to do? Should she try something thinner, to see if she liked those more? The thick ones she'd worn so far had been a bit much, though maybe only because she hadn't been able to ease her way up to them, the way she would have preferred. Even those seemed to have an endless number of options, however. Plus, she reminded herself after what was probably far too long, she didn't need another diaper, she needed to get home.

Then again, she didn't think Ms. Emily would like that answer, so she might as well accommodate the woman's wishes, right? She was already in enough trouble for making a mess of the play room! "I-I don't know," she answered truthfully. "There's so many!"

"Oh, sweetie," Ms. Emily shook her head. "If you don't choose, then you'll just have to stay in that one, even after you finish the little job you started there~!"

A light tap to the seat of Matti's diaper made it clear that the woman knew exactly what the girl had already done there. Matti blushed. She should have known better than to think she could keep any secrets here! She felt so outmatched, like a toddler trying to compete against a fully grown adult. That only made her feel more helpless, more overwhelmed by the choice she had to make. "C-Can't you choose for me?" she asked, hoping that would earn her some brownie points.

It did the opposite. "I thought you said you were a big girl who didn't belong here? And you can't even make this choice on your own? This is why you need to leave all decisions up to the real grown-ups, sweetie~."

"I am a big girl!" Matti answered automatically, stomping her foot and almost falling over.

Ms. Emily caught her, shaking her head like she would at any fussy little girl. "If you leave it up to me, then you're going in this one," she told her once she was steady on her heels again, plucking one from the shelf, so big and puffy that it, on its own, seemed even bulkier than the two she was wearing now. "Isn't it nice? It's the special, extra-thick kind I use for babies like you. Babies who are so hopeless, that there's no point even trying to potty train them, who are going to be stuck wearing their diapers forever and ever."

That wasn't what she was at all! And yet, hearing it out loud like that, having Ms. Emily say it with such authority, as if it was true, made her feel a bit dizzy. And, if she was being honest with herself, a bit turned on. How humiliating was that, the thought of a college girl like her, reduced to someone so childish, there was no point even trying to potty train her, in under twenty-four hours? "I-I'm not," she shook her head, wishing she could make it sound more convincing.

"Hmm," Ms. Emily arched an eyebrow. "Well, why don't we put this right here anyway?" She set the diaper down on the changing table, the message quite clear, Matti unable to take her eyes off of it as she shifted her weight nervously, almost falling over again. "You poor thing," Ms. Emily clucked. "You really ought to take my suggestion, dear, and try crawling. I think it would be more your speed."

"N-No, it isn't..." Matti protested. "I-I can... It's these..."

"You always have so many excuses, Mathilda," Ms. Emily observed. "But that hasn't stopped you from ending up here, has it? Perhaps this is all for the best, to help you accept the consequences of your actions. And you have plenty of actions to answer for, don't you?"

It was all too much for Matti to process, especially while her tummy was rumbling, desperate to empty itself at any moment if she stopped paying attention to it. Ms. Emily took her by the hand once more, leading her back towards the desk, leaving her in front of the smaller chair to step around and seat herself. "Sit down, young lady!" she snapped.

Instinctively, Matti obeyed, wrinkling her nose as she was reminded of the squishy spot in the seat of her pants, and finding that the chair was exactly the right height to prevent her feet from reaching the floor while she was in it, forcing her to put her whole weight on her backside. The principal's office vibes were stronger than ever as she anxiously adjusted her glasses, staring across the desk at Ms. Emily.

She'd always been a good girl, at least at school, and had, of course, kept her grades up, enough so to let her skip a year. She'd never been sent to the principal's office herself, but, in a way, that had made it even scarier. She always heard such horror stories, and whenever it happened on TV, it was an awful thing, and the longer she stayed away from it, the more it loomed in her mind. As a somewhat strange, petite girl with glasses, and, when she was younger, braces, she'd been an easy target for bullies, at least until she'd moved up to the same grade as her sister, who might not have always seen eye to eye with her, but didn't let people pick on her, she had been in the principal's office, though she hadn't been the one in trouble, and even then it had been terrifying sitting in there, knowing the person behind the desk held her future in their hands. It was so strange that that was exactly how Ms. Emily's office was set up, though maybe she was only viewing it through that lens because of her fear? Maybe this was what all daycare owners' offices looked like! If she didn't know better, she'd have thought this was the exact same desk as the one she remembered. That was surely her memory playing tricks on her, or a giant coincidence.

"Now, then, Mathilda," Ms. Emily said sternly, opening up her desk drawer and pulling out a piece of paper, one that, when she smoothed it against the top of the desk, Matti recognized as the fake report card her old nemesis Jasmine had made for her. She knew it was all made up, that she'd never gotten a D in her life, yet the card was filled with them, every one sending a shiver down her spine. "You come here with these dreadful grades, you lie repeatedly about being a big girl, you make a mess of my playroom... Clearly, you need some discipline. I have a feeling that, despite your grades, you're a smart girl, at least about some things. So tell me, Mathilda, what do you think I ought to do to you? Tell me the truth, or I'll have to punish you more. What does a brat like you deserve?"

"M-Me?" Matti squeaked. "Y-You're leaving it up to me?" That was somehow worse than it being completely out of her hands, especially with her brain still swimming with all the things she'd read in those diaper stories, that had made her feel so weird and tingly, fantasizing about them happening to her. This was her chance, but was she really brave enough to try any of them?

"I wouldn't say that," Ms. Emily replied. "I'm asking your opinion, that doesn't mean you have final say, though you should be grateful you're getting even that. Now, come on, Mathilda, what's your answer? And don't you dare say you don't know. You're not getting out of this choice so easily, young lady~!"

Ms. Emily was definitely enjoying watching her squirm, there was no doubt about that. Matti groaned, a sudden cramp hitting her and making her wrap her arms around herself as she desperately wiggled in the chair, her dangling feet not making things any easier for her. Any punishment was going to have to take that into account, too, but, unfortunately, there weren't any she could think of that she'd be able to finish up in time for her to go back to trying to figure out if, or how, she could use the spellbook as it was now with a relatively clean diaper.

And her diaper was already less clean than it had been, she was pretty certain. It was hard to judge for sure, and she was a bit scared to find out, but that mushy smear seemed to have grown a bit, spreading over more of her diaper, despite her best efforts. If she'd been in her normal underwear, or probably even trainers, not that she had any experience with those, this would likely constitute a full-blown accident already. It was only thanks to the size and bulk of her diapers that it felt somewhat small, and not too awful yet.

It was too bad that punishments were meant to teach a lesson, and that doing so took time. The quickest she could think of was a spanking, but that was also very painful, and would require her to be face down, bottom up, over Ms. Emily's desk, or, even worse, her lap, not only giving her a perfect chance to survey the damage Matti had already done, but get a front-row seat to any more that was bound to happen when she was given her second spanking of the day.

Time-out was easier. More childish, and still left her on display, but safer for her aching backside. She'd done that once already today, too, though it wouldn't be as bad to repeat. Was that really good enough to satisfy Ms. Emily? Probably not.

"I-I should clean up the mess I made," she finally spoke up.

"Yes," Ms. Emily agreed, and for a moment, Matti thought it was as easy as that. "You're going to be doing that, but that isn't your punishment, that's just being a good girl."

Matti looked around the room, barely stopping herself in time to keep from nibbling on her fingernail, searching for inspiration. It was clear she'd be going back into a diaper either way, and she'd already thrown away her chance to choose one for penance. The other wall, however, did provide some guidance.

"I-I should write lines," she said. "A-About being a good girl, and not making a mess."

"That's a start," Ms. Emily nodded. "Let's see, a board full of, 'Good little girls make messes in their pants, not with their toys,' would be lovely~. What then?"

Matti's lower lip had already been jutting out in a pout at the thought of filling the entire, gigantic board, so tall she'd probably need a stepstool to reach the top, and had pushed out further when she heard the woman's suggestion, and how every one of the many lines it would take to finish her task would remind her of what she knew she had to be getting very close to doing. But that wasn't even enough?! She had to come up with something else?!

"I-I should have some corner time?" It didn't sound quite as lackluster now, paired with the lines.

"Oh, yes," Ms. Emily smiled. "Quite a bit. And..?"

What else was there? She didn't know what privileges she had here, to be taken away, and she couldn't offer to go to bed early, not only because it was just past breakfast time here, but also because she very much doubted she'd be allowed to keep her book. There was really only one other thing she could think of.

"A spanking?" she sniffled, quietly resigned to her fate.

"What a good idea~!" Ms. Emily clapped her hands. "I know you just had one, dear, but obviously whoever gave it to you didn't do it right, because it didn't sink in. Don't worry, I'm sure I'm much, much more experienced than them."

Here it was, she thought. A whole range of punishments that, in the stories, had seemed like such naughty fun, now laid out in front of her, and feeling very different now that she was staring down the barrel of them. And she still had that giant diaper waiting for her at the end, since there was no chance of her holding it through all of that.

"I think you'd better get started, don't you~?" Ms. Emily chirped.

"Y-Yes, ma'am," Matti swallowed, sliding down out of the chair, carefully balancing on her heels. She turned towards the chalkboard, which somehow seemed even more gigantic now, and took one step towards it.

And then, all at once, it was over. She heard the grunt escape her lips almost before she felt the cramp, or realized her knees were starting to bend. A lump began to grow in the seat of her diaper, quickly beginning to spread outwards, oozing across her bottom. "No!" she squeaked, struggling with all of her might to make it stop, only to find it was far too late. Instead of standing up straight and crossing, her legs squatted further, the mass expanding faster as her body betrayed her, doing the opposite of what she wanted.

She couldn't stop it! She was completely helpless against it, no better than a toddler who hadn't even started potty training yet. Everything that had happened to her up until now paled in comparison to this experience. There was a reason this was always the signal of defeat in the stories, she realized. What could be more humiliating, more infantile, than this? Than squatting here, red-faced, pushing wave after wave of soft, squishy mush into her pants, feeling her diaper swell to accommodate it all, growing heavy and stinky between her legs?

She felt something between her lips, and, for a moment, she thought she was chewing her nails again, and assumed Ms. Emily was going to fuss at her for it, before she realized that, in fact, her whole thumb had slipped into her mouth. Had it been an accident? Or was her mind recalling when Jasmine had made her suck her thumb earlier today, and how soothing that had felt after her spanking? It felt even better now, enough so that she didn't care how babyish it made her look. At this point, what difference did it make?!

Finally, after what felt like an eternity, it ended, and, slowly, Matti straightened up, actually managing it this time, though her feet felt wobblier than ever in the heels, the extra bulk in her diaper pushing her legs further apart. Her thumb was still firmly in her mouth, and the sensations coming from her diaper were still overwhelming, but her tummy did feel much, much better, as did her mind, now that she could afford to use it to think about more than trying in vain to hold her bowels.

That sense of relief was so strong, in fact, that she nearly forgot where she was, and what was going on, until she heard a voice behind her. "Oh, Mathilda~!" Ms. Emily called in a playful voice. "What just happened there, little one~?"