Frisk's eyes fluttered open, and she realized she was laying in a bed of golden flowers. For a moment she felt like her whole body ached.. Then she felt like it was only her heart.. Then she felt fine.

She sat up in confusion, looking around at the cave. It only took a moment to realize what had happened, and her eyes began to fill with tears. A lifetime of fuck ups and she hadn't even been able to die right.

She didn't know how long she sat there in that flower bed, sobbing and wishing she could feel nothing.

Eventually, though, that strange ache in her chest returned, and didn't vanish until she'd gotten to her feet and started off down the hall.

At the end of the hall she passed through an archway into another, darker cave, finding another of the yellow flowers. As she approached it, though, she was confused to see that it… had a face.

"Howdy, I'm Flowey, Flowey the Flower!" It announced in a rather adorable voice, "I'm your personal guide to the Underground!"

"The.. the Underground?" Frisk questioned, eyes widening as she realized where she was, as it dawned on her what it meant to be this deep inside the mountain. Humans told stories of the monsters, those sexually deviant creatures who lived lives of debauchery and would assault any human they came across, using them for their sick pleasures.

But.. this flower didn't look so threatening.

"No need to be scared, I'm here to help," Flower assured as a strange glowing dust began to spread out from their body.

Pollen maybe? Whatever it was, Frisk's body began to feel warm, her body fidgeting as that feeling she'd tried to ignore all her life began to rage inside her again.

Her legs began to shake as she felt her sensitive nipples harden against her shirt. The warmth between her legs began to grow hotter and moist, and worst of all, her cock began to harden; something she could only associate with fear and pain because of how she'd been treated growing up. Usually anyway… this time though, she felt strangely okay.. Safe.. warm..

She was undressing herself before she even realized, legs rubbing together as she desperately tried to tend to her burning body.

"My special pollen will get you ready to take on the Underground," Flowey said.

The new desire burning up Frisk's inside was only slowed as her eyes fell on the floating heart that now hovered at her chest.

Like an obstacle illusion Frisk couldn't say for sure if it was flat against her chest or hovering in front, but it pulsed gently, with what looked like faint cracks that had been filled in with a darker shade of red.

"That's your soul," Flowey explained as Frisk gazed into it, with the strangest sensation that she was.. Meeting someone new, "Its the very culmination of your being. Right now your soul is weak, but I can help you make it stronger. Would you like that~?"

Frisk shivered at the tone that had crept into Flowey's voice, and looked down to see slender green vines slowly working their way up Frisk's leg. Frisk bit her lip, uncertain about the situation. It didn't seem right to trust a monster, but she felt so strange.. And so excited…

"O-okay." Frisk said, holding still as the vines wrapped around her entire body. Frisk gasped as suddenly the wind was knocked out of her, the vines fastening like a straight jacket as the little yellow flower began to laugh.

"You idiot! In this world it's take or be taken, and now I'm gonna take that body of yours as a plaything!"

More vines those from the ground, these much less inviting. Thick as weightlifters arms and rough like stone, some even sprouting thorns. It didn't take Frisk long to realize where said vines were aiming and intending to do, and her eyes began to water again despite having only just dried.

She closed them, listening to the monster's laughter as she waited to be killed by its sexual torture, feeling it was what she deserved for being so stupid. But the monstrous vines never reached her.

Instead, a wall of fire rose in front of her, the heat forcing Frisk to open her eyes and see it.

As the vines recoiled, the wall collapsed into a single ball of focused flame that launched like a cannon ball at Flower, sending the little Flower monster flying away into the darker parts of the cave.

Frisk panted heavily in relief, though her body still shook with need as she looked towards her savior.

She half wondered if her eyes were being affected by the pollen as well, as she couldn't imagine a monster that looked so beautiful as the tall goat-like woman approaching her.

She was wearing a long purple dress, but it hugged her body perfectly to leave exactly enough to the imagination, making Frisk-or at least her desire infected body-want to rip it off and explore every inch of her delicious milfy body.

"What a horrid creature that was," the monster said as she knelt down, bringing Frisk against her, "Allow me to put you at ease. My name is Toriel, I tend to all those who fall into the Ruins." She explained as she reached down, wrapping a gentle hand around Frisk's throbbing member and beginning to work up and down it slowly.

She whimpered at the pleasure, member twitching at how soft her hand felt, how skillfully it pumped up and down her length.

She reflexively flinched when she saw Toriel's hand seemingly erupt in fire, but she felt no pain, only a strange, intensely hot pleasure that spread wherever it touched Frisk's sensitive skin. Within seconds of feeling it her tip was leaking with precum, and in under a minute she'd erupted, covering Toriel's hand in thick, pent up cum.

Toriel giggled, bringing her hand to her face to lick it clean as casually as you'd down a drink from a trusted friend.

"Human cum does wonders for a monster's magic. You'll have to forgive some of the others here, a human's soul can rile us up." Toriel explained further, helping Frisk to her feet.

Her mind was clearing now, and she suddenly felt extremely nervous and shocked by the situation, unsure what to say or do.

"You may get dressed if you want, but are by no means obligated." Toriel said, turning to lead Frisk onward through what she supposed was called the Ruins.

Frisk hurriedly dressed herself and followed the goat monster into the next room.

"The Ruins is a maze of hallways, traps, and puzzles," Toriel explained as they entered a room with seemingly no door. Instead there was simply a dead end brick wall, with three statues on the floor of what appeared to be erect members; two pointing away from the wall and one pointing at it.

"Let me demonstrate." Toriel said, moving forward and carefully stepping between the two cock statues pointing away from the door, raising her bare foot and pressing it down on the rigid stone cock aiming at the door. She began to work her foot back and forth, stroking the statue cock tenderly.

Frisk watched in awe as Toriel worked the faux cock with her foot until it seemingly came; though instead of releasing stone cum, the doorway opened up, allowing the two into the next room. Toriel took Frisk's hand and guided them through.

If Frisk even described something like what she had just witnessed in a human town she'd likely be killed for being so deviant.

Perhaps it wasn't that monsters were evil… perhaps they and humans simply disagreed on what was and was not evil.

In any event, the next room contained little more than what looked like a sex doll of a hermaphrodite.

A remarkably lifelike one that could be mistaken for a living person… and now that Frisk thought about it, considering the Flower had been alive, perhaps this doll was as well. It seemed not though, as Toriel explained that it was for testing one's skills.

"As I said, monsters are rather riled up by the aura of a human, as it awakens a deep thirst for their release. However, if you learn to placate them with more gentle fun, I can catch up and scare them away." Toriel told Frisk, beckoning to the doll for Frisk to test out.

Frisk stepped closer to the doll, and slowly reached out to feel it. It felt surprisingly life-like, warm and soft to the touch. Her hands moved across the doll's body, Frisk following Toriel's instructions for how to massage the doll's chest, rub and lick their pussy, kiss and suck their sack and member.

All of it was slow and tender, and took a few tries for Frisk to get the hang of; but she learned surprisingly fast.

Toriel smiled proudly, "You'll do wonderfully." Toriel said, beckoning Frisk to follow. In the next room Toriel had Frisk memorize the patterns on the walls before showing her through a seemingly empty path, having her walk the path she'd memorized.

Once they'd reached the other side, Frisk curiously took a stone from the floor and tossed it out to the floor. Once it landed, slick tentacles as thick as logs manifested magically, lounging at the stone from all angles.

Upon finding no holes to violate, the tentacles launched the stone off the path before vanishing once again.

Frisk, now much paler than she'd been, turned and followed Toriel to the next room. There she had no test for Frisk, but a gift; a phone. It could take pictures, record videos, text, and call anyone she had the number of.

"This way you can contact me wherever you go. This room is protected by magic, so you'll be safe here. Stay here while I head through and prepare the house for you. If you do end up on the other side, there's a room nearby with Monster Candy. It'll help you get somewhere safe."

Frisk wasn't sure how candy would help keep her alive, but figured it was best to have everything she needed on hand.

So within moments of Toriel's leaving, Frisk snuck through slowly, finding the bowl of monster candy and taking three pieces for later.

On her way back to the door, though, she felt that dull ache in her chest again, and found her body moving before she knew why. Right where she'd been standing landed a monster.