It was young Harry Potter's first time on the train en route to Hogwarts School of Witchcraft and Wizardry, and he was excited to see the castle for himself. The very concept of Magic was still new and wondrous to the 11-year-old boy who grew up with no understanding of his potential, or the relations between Wizards and Muggles.
He'd taken a train car for himself after being separated from his new friend Ron Weasley at Kings Cross after he excused himself to the restroom. He hoped Ron would follow up on their meeting and join him, it would be nice to have some friends going into an unknown environment such as Hogwarts before he arrived.
After riding on the train for about twenty minutes, Harry noticed an odd glowing coming from inside of his right pocket. Reaching into and turning out his pocket Harry discovered that his new wand was responsible for the strange source of light. He flicked his wrist trying to turn it off, still not having a handle on the use of magic. However, the light only appeared to grow larger and glow brighter as a result.
When the light finally began to fade Harry could tell immediately that something was amiss. His legs had shifted position and he felt as if he was now sitting on a flat surface. Upon rubbing and opening his eyes Harry discovered why. The small train car he had been riding in earlier was now gigantic in size, large enough to contain the Dursley's entire home, along with most of the surrounding neighborhood.
Harry had been shrunk down to an inch tall in height, sitting height about the floor in the seat he was occupying earlier. But with nobody around to witness his shrinking or any way to get to the floor from his current location, Harry felt as if he might be stuck small for some time. Fortunately, his wait might not have been as long as he feared, as the door to the train car clicked and slid open to reveal a young girl. Her name was Hermione Granger.
She wore a Hogwarts uniform and robe paired with a formal skirt that reached down to her knees, complete with a black robe. Hermione peered into the room, swearing she had seen a flash of light, indicating that someone was performing a bit of magic in here but the room appeared completely empty. Oh well, at least she'd finally found a nice place to sit down and rest until they arrived at the castle.
Hermione wandered in, sliding the door closed behind her and pulling down the blinder on the door for privacy reasons before turning the face the seat on her left. "This is perfect, she's looking right at me." Harry said to himself, hoping he could get her attention and return to his normal size as quickly as possible.
Harry jumped up and down, waving his arms and yelling up at Hermione in the hopes that she'd notice him. However, her eyes neither widened nor blinked as she took two steps towards where the famous young wizard had been sitting. She easily towered over him at an astonishing height as she turned to sit down.
"Bollocks!" Harry's said, the look on his face turned from one of hope into one of fear as he recognized that he was too small to be seen without being looked for. It probably didn't help that his clothes bared a similar pattern and color to the fabric covering the seat. A lot of good this new information would do him now that the massive Miss Granger was no longer looking at her new seat, already straightening out her clothes and extending her bum out towards Harry.
There was no time to react, Harry tried to run away but Hermione's bum easily bulldozed over him like he wasn't even there. Good thing he had the instinct's to fall on his back as Hermione landed on top of him, otherwise his spine might have been broken in two. Another thing to be grateful for was how strong Wizards bodies were by nature, any normal human being would have been crushed like an ant under the young witch's bottom. Trapping him somewhere under her right buttcheek.
Even through the fabric of her skirt and knickers, Harry could feel just how soft Hermione's flesh really was as she began to adjust herself to her new seat. Strangely enough, it already appeared to be set to the shape of another person with a slightly smaller butt than her own, telling her that someone else was in her recently but they must have moved on. Nothing a few quick movements wouldn't solve.
Hermione grabbed her seat and pulled her weight in a downward spiral, hoping to conform the bench's cushion into the shape of her rear end. Harry's experience of this was much more dramatic, Hermione's bum going straight from bulldozer to steamroller as she forced all of her weight down on him, twisting and turning in her seat.
"Ahh, much better." she announced, lifting her butt upwards slightly to fix her skirt before sitting down again. Her crushing weight removed from Harry's tiny body for only a mere second before her rear end came crashing down all over again, accompanied by a sigh of relief from the young girl as she made herself comfortable.
Hermione reached into her bag, pulling out a book on charms and spells she'd purchased at Flourish and Blotts in the hopes of getting in a bit of light reading before they reached Hogwarts. Of course, to someone like Hermione the term 'light reading' was loosely defined as the book added over five pounds to her overall weight upon being set on top of her thighs.
What will happen next?
1. Hermione feels something moving around underneath her, getting up to find Harry sprawled out on her seat. She starts off nice and sincere as she apologizes for sitting on and flattening him with her bum. However, after giving her name and learning his true identity things take a turn for the worse as Hermione wonders what such a famous person was doing under her butt in the first place.
2. Harry wand begins to glow again from inside his pocket, activating a new spell that makes him slip through Hermione's skirt. Landing him just outside of her knickers as she rides the train unaware of her tiny passenger. Once the train stops, Harry finds himself stuck to Hermione's skin by sweat.
3. Hermione feels something under her and gets up to discover a moving creature under her butt, without examining him more closely she determines that he must be one of the chocolate based products she's heard about. Such as the chocolate frog, a spell placed on them makes them run from the mouths of whoever attempts to eat them, but they aren't actually alive.