One day in ponyville, Spike was left alone at the golden oaks library while Twilight headed to Canerlot for an urgent meeting with the princesses. She had been in the middle of studying a cache of hidden magical artifacts that she'd found beneath the library, most likely left by the last occupant, when she was called away.

Spike, being a curious little drake, decided it wouldn't hurt to take a peek at whatever had gotten twilight attention for the better part of a week. So he waited until his sister was gone, then snuck down to the basement to snoop around.

Among the myriad of strange artifacts and doodads he found scattered about Twilight's research area, there was one in particular drew his eye. It appeared to be, for all intents and purposes, a huge, poofy diaper. It lay folded up on the table, surrounded by books, scrolls, and a load of research material. More than likely it was the last thing Twilight had been working on, though Spike could hardly fathom what the unicorn was doing studying something as lame as a diaper, of all things. Strangely enough, Spike could swear it was glowing.

Disappointed at not finding anything interesting, Spike went to walk back upstairs, but froze in place the moment the diaper was about to leave his field of vision. Try as he might, he couldn't look away and soon found himself taking a few steps forwards. For whatever reason, the little dragon was drawn to the diapers, some force urging him on to investigate it and causing his body to move towards it with little resistance.

 However, when he drew close, the diaper appeared to come to life and launched itself at him! Spike was caught off guard and was unable to put up much of a fight. In seconds the poofy padding was taped securely onto his rump and released a soft flash of magical light. A soft clicking sound echoed from the pamps just as the tapes stuck themselves in place, drawing Spikes attention to the lock symbols that appeared to be printed on them, emanating a soft magical glow.

The baby dragon tried desperately to remove the babyish underpants , blushing furiously the whole time, but to no avail. No matter how much he pulled, yanked, scratched, or burned, the pampers were no worse for wear and still firmly stuck to his rump. He huffed in embarrassment and anger, glaring down at the babyish undergarments that now forced his legs into a wide stance. He wouldn't be doing anything but waddling anytime soon, it seemed.

"Grr... Stupid diapers! Why won't these dumb things come off?!" The dragon muttered angrily to himself.

Moving to Twilight's workstation, Spike grabbed a scroll and a quill, ready to send a message to Princess Celestia about his issue. Now, obviously he wasn't going to tell the princess that he needed help getting out of some apparently cursed diapers! No, that’d be mortifying! He would just ask the princess to tell Twilight that he'd run afoul of her latest project and needed her help.

Normally Spike wouldn't dare to risk anyone seeing him in such a state, but Twilight had drilled it into his head to be careful with cursed artifacts, so he knew the longer he was in contact with it, the greater chance of danger or an unknown effect was.

However, it seems he was already facing one of said effects, as when he was about to start writing the letter, he stopped. Spike's brow furrowed and his nose scrunched up in confusion as he held the quill over the paper. He knew what he wanted to do, that he needed to send the letter, but for some reason... he couldn't. Not that he physically couldn't, no not at all. He could still press the quill to the page and make a blot of ink. It's just that whenever he tried to write, the words just... wouldn't come. For the life of him, Spike just couldn't remember how the heck he was supposed to make words appear on the page!

"W-what the...?" He muttered. "Why can't I... How do I write stuff again? I-i swear I know how, I just did it this morning!" Spike glared angrily at the blank paper, as if his stare alone would make his message spring forth from the ether. After words failed to magically appear, however, he turned his gaze to the papers scattered about Twilight's workspace. The clever little drake was guessing the new poofy pampers around his waist had something to do with his inability to put down words and figured looking at the notes already on it may shed some light on the situation.

As he looked at the papers, he let out a relieved sigh once he saw he could actually read them. Well, most of them. There were lots of big words scattered around like 'cognition', 'superposition', and 'alteration', among others. Those took him a little while to read, if he could even understand what they meant. He... honestly didn't know if this was the diaper's fault or his own lack of linguistic prowess.

Regardless, he was soon able to get the basic gist of what the cursed items did and felt his heart sink the moment he did. In a flash, Spike grabbed all the notes Twilight had on the cursed artifacts and sprinted his way upstairs. Or tried to at least, as his gait turned into a severe waddle as a result of the pampers strapped around his rump.

As he reached the main library floor, he dumped the research on the ground and began ripping books off the shelves, everything and anything related to enchantments, curses, and how to break them. Soon, he had amassed a small pile and frantically flipping through them to find a way to remove his new diapers. Why? Well, because when he read Twilight's research, he discovered the artifacts had been designed as a means to harmlessly neutralize a dangerous threat by returning them to a harmless, infantile state of mind.

That is to say, the diapers were cursed to turn anyone who wore them into a pants piddling, drooling baby. And unfortunately for Spike, he was wearing them.

"C'mon, c'mon! There's gotta be something in here that can help!"

Spike desperately searched every tome and scroll he could get his claws on for something, anything that could help him, but could not find a single thing. All the curse removal books required powerful magic of some kind to perform a cleansing spell, or some obscure reagents he didn't have or where impossible to obtain. What's worse, the more Spike read, the more he started noticing himself slow down.

As an assistant to an avid bibliophile, he was fairly well read, with a rapid reading speed. He could prolly get through a couple books in an hour or two if he really wanted too. Nowhere near as close as Twilight, but still impressive. Now, however, he found himself struggling to get through a single chapter in that same amount of time. What's more, he kept getting distracted by every little thing!

Animals outside, the sun shining off a particularly shiny piece of metal, or even the colorful books stacked over by the foal's section! He was running out of time, and Spike knew it. His panic was slowly rising, causing him to subconsciously bring his claw up to his mouth and pop it in. Immediately, he felt better, as he began softly nuking on his thumb. He relaxed, his eyes drooping as he felt his previous stress and worry slowly melt away with each suckle.

What was he even worried about? Being a baby wouldn't be so bad. He'd get to relax and do nothing all day, playing with toys, taking naps, and getting coo'd at and cuddled by everyone. Maybe even by Rarity!~ All he'd have to worry about is looking cute and whenever his next diaper change would be…

...

Diaper change?!

Spike's eyes shot wide open in shock. No way! He wasn't some dumb hatchie! He was a big boy and he didn't need diapers! He needed to find a solution and FAST!

As he sat there, claw still firmly in his maw, and a new book open in front of him to resume his search, the dragon's thoughts turned to Twilight, the whole reason for this mess he was in.

'Dangit, Twilight! Who the heck leaves a bunch of cursed diapers lying around without tellin' anyone?! I gotta hurry up and figure out how to take these stupid things off before they make into a real baby dragon!'

Narrowing his eyes, Spike looked down at the strange papery thingies in front of him, eyes scanning the weird markings doodled all over them with an intense focus.

‘Hopefully the answer’s somewhere in these weird square thingies Twilights always lookin' at. Dunno how a buncha squiggles are s'posed ta help me though...'

However, after a couple of minutes of intense staring, nothing seemed to be happening. Feeling worked up, Spike began nuking even harder on his claw, trying to calm the frustrated feelings building up in his chest and barely keeping the building pressure behind his eyes at bay.

'D-dawn it... W-why can't I undastan' dese squiggwy tingies!'

Spike wiggled around in discomfort, feeling another type of pressure building up somewhere inside of him. He was too busy pondering his conundrum to really take much notice of it, however. Instead, he continued to suck his claw and glare at the paper. Unbeknownst to the drake, his usual emerald green eyes began to glow softly, the same shade of magic as his cursed pampers. Slowly, a swirling pattern of colors began to fade in overtop them, spinning softly and pulsating in tune to the magic.

'G-godda... Godda get dis diapee off.. I...imma big dwaggie, notta dumb baybee! Dun need, uh... D-dun... Dun need... D-diapees gettin' wawm...'

It was at that moment that Spike's resistance broke completely and his eyes were completely replaced by the spinning spirals. At the exact same time, the pressure in his body magically disappeared, causing a relieved sigh to escape the baby dragon and a dopey smile to spread across his face.

His pamps, previously a pristine white color, began to discolor and swell as the little dragon emptied his bladder into his pampers, along with all of his big boy thoughts and knowledge. Every story he'd ever read, every lesson he'd ever learned, and every thought he'd ever had was slowly being flooded into his diapers without a second thought. And the whole time Spike simply sat there dumbly, giggling softly to himself as he experienced his first accident in years and all his words, numbers, and thoughts were piddled away into his thirsty pamps, his earlier panic and desperation among the first to go.

'Hehehe... W-wawm diapee...squishy...W-wuv diapees... I wuv my diapees! Hehehe...'

And with that, Spike the dragon, number one assistant to the element of magic, was reduced to nothing more than a babbling, drooling, piddle pants hatchie. Not a thought in his adorable little head left except for how much he loved his diapees.  All the worry he'd had before had vanished alongside his big boy thoughts, faded away along with his diapees' patterns.

Before long, Twilight would return home to find an adorable little baby dragon in place of her assistant, laying  on his back in his thoroughly soaked pampers and happily chewing up her research on the cursed garments between his legs, ensuring he'd never grow up ever again.