For Starlight it all began with the letter from Sires' Hollow, a letter delivered to her shared residence at the most importune time. One of the downsides for the unicorn in not having a place of her own in which to dwell, was that mail addressed to her had to be dropped off at the front doorstep of the castle. And that meant if she wasn't there when it was delivered or wasn't fast enough, at least one set of prying eyes would pick it up and bring it to her. Often with either Spike or Twilight at least wondering what the letter said.

And as luck would have it, the letter was one of many Starlight had been receiving from her dad after she'd addressed her complicated relationship with him (and promised to visit more often). If the energetic horn writing wasn't a dead giveaway, the tone of the letter definitely was. It read as follows:

To my precious little princess, Starlight Glimmer

How are you? I know we've been keeping in touch through letters, but Stellar Flare's been helping me with scheduling lately and I noticed that it's been weeks since you came back to Sires' Hollow for a visit.

Could you please come and stay for the week? I've got a very special surprise waiting for you, and I think you're very much going to like it.

Plus, you'll be amazed at how much things have changed since you last visited. And don't worry, your old room's still just like you left it, Punky Wunk.

Here's to seeing you soon, hopefully,

Your loving father,

Firelight

Twilight and Spike knew only a little about Firelight, but they nevertheless had some suggestions for Starlight once she'd finished reading the letter and had set it aside.

"You don't have to visit him if you don't want to," Spike suggested. "I don't think Sunburst is available for another trip back to home. And I'm guessing you still haven't told Trixie about your dad yet."

Starlight shuddered internally at the very thought of Trixie learning of her childhood home, especially if she were to meet her dad (who would no doubt share many of the embarrassing nicknames and memories). She firmly shook her head.

"All the same, he is your father," Twilight pointed out. "You could at least go for the day, and then come back by nightfall. It would leave you more open in case a friendship problem arouse somewhere. Plus there's your guidance counselor position that would be need to filled. And after you managed so well with Cozy Glow, it's clear you have an approach that can't be duplicated to any extent. I'm sure your father will understand, now that he's not treating you like a filly."

But the unicorn mare with a light purplish-grey coat merely sighed and flatly protested. "I made a promise to visit more often if he agreed to treat me like a friend and not a filly. I may not care for his overly embarrassing nature, but a promise is a promise. And he's right that it's been a long time since I visited. I managed an entire childhood with him, I can survive a whole week on my own," She was quick to add. "But I can always teleport back to Ponyville in an instant if I'm needed. I doubt anything will come up, but you just never know."

"Are you sure you don't want either of us to come with you?" Twilight offered to her former student. "Spike and I wouldn't get in the way, but it would be nice to get to meet your father face to face."

"No thank you, Twilight," Starlight rejected the offer, even though a part of her found comfort in the idea of traveling with company. "Whatever this 'surprise' my dad has in store for me for the week, it can't be any worse than facing down Queen Chrysalis or trying to solve a friendship problem between the royal sisters."

Twilight reluctantly nodded her head. "Very well. Just know that you can write me or any of our friends at any time if you need someone you trust to talk to. We're not going anywhere."

Starlight was back in Sires' Hollow the very next day. And although the massive gate was still there to greet her, she was quite relieved that Stellar Flare had removed the voice that repeated "Welcome to Sire's Hollow!" whenever it was opened. That was one change she was glad had been made.

As she trotted down the road leading towards her home, saddlebags in tow, the mare couldn't help but marvel at what had become of the town in her absence. The essence stand had now turned into its own shop, and between it and the fruit smoothie shop, was a grocery store. Sire's Hollow had only had a market place before. And the store itself easily dwarfed all other buildings in the area from sheer size alone.

Even Sunburst's childhood home had undergone a renovation, no doubt at Stellar Flare's insistence. It seemed like a few rooms had been added, and the color of the bricks were now much more vibrant and welcoming.

But just by glancing along the horizon, Starlight could tell that her home hadn't changed. And when she came trotting up to the front door, who should come running to embrace her but Firelight himself?

"Starlight! So glad you could make it!" He happily exclaimed, pinching her cheeks out of habit. "My oh my, just look how big you're getting!"

Starlight let out a groan of frustration. "Dad, remember the talk we had about me being a grown mare?" She reminded her with a glare in her eyes.

"Oh, of course. I'm sorry, old habits die hard," Firelight apologized and lessened his grip ever so slightly. "I've just missed you so much!"

The unicorn mare muttered under her breath. "I can tell." But Firelight, thankfully, didn't hear.

With a gleam in his brown eyes, the stallion with a coat a darker shade of grayish-purple than his daughter finally ended his hug. "I think you're going to like your surprise, Starlight," He spoke in a tone that sounded not unlike a coo. "I've been planning this for quite some time."

Reluctantly, Starlight followed her dad inside as he took hold of her saddle bags with the brilliant gamboge glow of his horn and held them high over his wavy mane and tail of moderate and pale, light-grayish aquamarine. All the while, she kept thinking to herself. "Please don't let it be anything too embarrassing! Please don't let it be anything too embarrassing! Please don't let it be anything too embarrassing!"

Firelight took the liberty of depositing his daughter's saddle bags in the living room once both were inside. Starlight hoped to at least make some small talk with him for a bit, maybe catch up on what her old stallion had been up to. Truth be told, she wasn't really looking forward to her surprise. Whatever it was, she had a feeling it was going to be something she wouldn't forget for all the wrong reasons.

Alas, as if fate itself were working against the unicorn mare, Firelight simply ushered her down the hall and to her old bedroom. When the door was pushed open, Starlight could see that it was indeed still like it was the day she'd left town. Bat pony plushies, guitars, anything to do with darkness, and even a few well worn kites littered the walls and floor. Her bed sheets even remained un-tucked in.

But what really caught the mare's wandering blue eyes, was what lay at the far end of the room. What she saw filled her with dread. A couple of her foalhood toys and dolls rested in their own little corner, next to a bright purple pacifier that was clearly intended for a sized up foal. But most telling of all, was a great big package of unopened Silly Filly brand diapers in all their infantile glory, complete with the necessary supplies one might need to care for a big foal.

Starlight blinked and rubbed her eyes, hoping beyond hope that she had imagined things. But when she took another look she saw clear as day that the foalish items were still there. She cursed under her breath. "So this is my surprise?" The unicorn guessed, turning to face her father. When he confirmed her worst fears with a nod, she let out a groan of frustration. "Dad, I thought I told you that I'm a grown mare!"

"Oh of course you are, Pumpky Wumpkin! But you'll also always be your daddy's little star," Firelight cooed and pinched Starlight's cheeks. "You had it rough when you were a foal. After your mom died while you were still in diapers, I was never around. I was always busy working just to support you, and left you in the care of Sunburst's parents. So I figured: 'Since I can't turn back time or turn you back into a foal, this is the next best option.' I even sized up your old diapers and pacifier just for you."

Starlight put her hooves to her face. "I appreciate the thought, Dad, but I'm not interested in being a foal again. I had one childhood, and it was unpleasant enough as it was. I've no interest in going all the way back and pretending to be a foal."

"You sure?" Firelight asked, reluctant to let the idea go. "It'd only be for the week. I'll even let you wear your favorite blankie if that'll make you feel better about all this." He proceeded to hold up the same kite patterned blanket his daughter had worn when she was little.

Despite feeling an extremely strong nostalgic attachment to the soft object, Starlight still wasn't willing to let herself be tempted into doing what her father wanted. "I didn't agree to this, and I never would've come here if I'd known this is the surprise he had in store for me. This is exactly why I've been dreading coming back to see him again." The mare thought to herself and started to trot towards the bedroom door to leave.

However, just before she reached the door, another thought entered the unicorn's mind. "Then again, I did promise to stay for the week. And Dad hasn't exactly been the kind of stallion who takes no for an answer. At least if I agree, it'll be on my terms and not his," Even as she moved a hoof to the door and prepared to trot through it, she found herself slowly and reluctantly turning around to face back towards her father. "I'm probably going to regret this by the time the week is over." She thought, and mentally prayed that wouldn't be the case.

With a sigh, Starlight accepted the blanket and finally gave her response. "I suppose if you really wanna do this, then as long as it's just for the week I guess I won't mind it too much."

Firelight let out a cry of joy, hugging his daughter tightly. "Oh thank you, Chipmunk Cheeks!"

Throwing up a hoof to stop her father from pinching her cheeks, the mare with a light grayish-purple coat protested. "But I have a few conditions that you have to respect, or else I'm throwing off my diapers and booking the first train back to Ponyville. Got it?"

"Oh of course, of course. I want you to be comfortable after all." Firelight nodded with a smile.

Starlight proceeded to immediately lay out her terms. "First and foremost, I am NOT using my diapers at all!"

"Does that mean you're going to use the potty?" Firelight cooed, using the rather foalish term.

Starlight blushed and groaned. "The bathroom," She corrected. "And yes, I will. All by myself too, I don't need help. So don't get any ideas."

"Fair enough," Firelight conceded. "Now, shall we get you all nice and padded up?"

"Not yet, you didn't let me finish!" Starlight firmly protested, struggling to control her blush. "I'm also not making foal talk, or babbling, or cooing, or anything like that! And if I'm going to do this, you have to promise me that this stays between the two of us! That means no taking me out in public while I'm in diapers!"

"Wouldn't dream of it, honey bun," Firelight agreed, then added in a cooing tone. "Though I think Stellar Flare wouldn't mind seeing her favorite little filly again."

"Dad!" Starlight half groaned/half whined, her blush raging out of control and spreading to her cheeks.

Realizing his mistake, Firelight quickly apologized. "Oh relax, Pumpky Wumpkin, of course I'm not gonna let Stellar see you in your diapees. You have my word, this will just be our little secret."

"And that brings me to my final term," Starlight firmly spoke up, her blush slowly dying down. "I'll put up with everything else in the treatment, but you better not take any pictures or tell anypony about this. If you do, I will never forgive you and never come to see you again. Are we clear on that?"

"Crystal," Firelight happily nodded, and then he instructed. "Now lay down for me and hold still, little star. Daddy will get you all nice and padded up."

"What have I gotten myself into?" Starlight thought, as she reluctantly obeyed her father's commands. This was going to be a long week.