It was sunset in the Firefly Forest. Kephis, a young elven man of about fifty, poked the suspicious tree with his staff as fireflies moved out of the way. His staff went right through it, and the tree itself turned transparent, revealing a hole with a ladder inside it. Even some of the fireflies revealed themselves to be illusions as well, turning transparent along with their tree.
This was concerning; nobody had ever found an illusory tree in the Firefly Forest before. Someone or something was down there. Or perhaps it had been abandoned long ago and there was something wonderful left in there.
As curiosity overcame him, he abandoned his rare mushroom gathering expedition to investigate. Despite his slim musculature, he was a master with a staff, and his borderline mystical swings were powerful enough to knock a bear onto its back. He would be fine.
He reached into his backpack and pulled out a permanent torch--a magical, perpetually-glowing glass orb on a stick--and descended down the sturdy wooden ladder.
~~~~~ ~~~~~
The ladder took him thirty feet down into the bedrock itself, and in front of him was a narrow tunnel six feet wide and just barely tall enough for his head. His permanent torch shone about forty feet ahead, and there was no end. He carefully felt the walls and tapped the floor with his staff, in case there were illusory traps set. The last thing he wanted was to fall into a pit trap and get impaled. He'd probably survive it anyway; as both an elf and a martial artist, Kephis was built differently.
Then a giggle.
"Hehehe..." he heard a woman say from the darkness beyond. He froze. Someone knew he was here.
"Hello? Helloooooo?" he said as he stepped forward. The tunnel started to widen as he traveled through it, although something didn't feel quite right.
He kept walking. The tunnel got bigger and bigger, and he started to feel dizzy. What was going on?
"Hello?" he asked again.
The tunnel doubled in size as he walked, then tripled in size, and as soon as it had quadrupled in size, he noticed that the bedrock ceiling was above where the natural bedrock layer was supposed to end.
He stopped walking to ponder the situation, but as he looked up at the ceiling, it kept getting farther and farther away, much to his horror.
Either the tunnel was magically growing...
...Or...
Then the giggle came back.
"Realized what's happening yet?" a cute voice said.
Kephis was now less than a foot tall, and he looked up and stumbled backwards in panic as the tunnel lit up with purple light, revealing a green, busty, nude slime girl in a black witch hat. Unlike most slime girls, she had proper legs instead of a mound of goo; the mark of a powerful slime. She didn't have any kind of opening where one would have been on an elf woman, but her genitals were far from the main thing on his mind.
He was still shrinking, and finally, once he was six inches in height, it stopped. He looked at his staff, barely bigger than a toothpick, then looked up at the human-sized slime girl towering above him. Violence was not an option, at least not for him.
"I don't mean you any harm, I was just investigating, and--"
"--Oh, I know. I keep an eye on what happens in this corner of my woods."
"Your woods?" he asked, almost forgetting that he was tiny. "We elves are the proud caretakers of--"
"--Do me a favor and shut up. Now, if you were to try and run, you might make it ten feet before I walk up to you and step on you or something. You may be the size of a bug, but the magic makes sure you won't have the annoying speed of one."
"What do you want with me? If you want me to leave you alone, I can..."
"I want a playmate," she said, and he shuddered. "Someone I can do... this to."
She reached forward, and before he could turn around and run, she managed to pick him up in one gooey hand. Her grasp was loose and playful, and he did his best to wriggle free.
He stammered out whatever words came to mind as he struggled, but as her slime seeped through his clothes and clung to his body, it grew harder and harder to struggle.
"Hey, hey, there's no need for--" he said before she interrupted him.
