You're a human that has fallen into Mt. Ebott on the year where all humans dress as monsters...Halloween. So how will the monsters know if you're a human or not?

He killed them all. Dust, down the waters of the the forest it runs, through the veins of the skeletons and the demons that prowl the night. It's the silent enemy, the adversary that slowly chokes and brings down entire armies to their knees. None can oppose it for none have the will or the strength. And it is the dust that emerges from the mouth of a mountain that overlooks a city, the dust that creeps and crawls through the forest and down the alleyways. It is the dust that wraps its bony hands around the throats of the damned ignorant enough to walk the streets, squeezing until the last heartbeat thrums. You are a detective in this city, a quaint area with little crime and a police force hopped up on Dunkin Donuts. But when a string of murders plagues the town, you are thrown on the case following cold leads and an ominous trail of dust. But one night, when you catch wind of a scream and follow it through the dark, you find a skeleton and the rest is history.

It's only been a few years since monsters have been released from their underground prison. In some towns, monsters are welcomed with open arms. Others? Not so much. Y/N is a 22 year old girl that lives a pretty simple life. Sleep, eat, work, relax at her daily cafe, go home, sleep. Then the routine starts again. However, her routine is thrown off when she keeps running into a skeleton, supposedly named Sans. She would like to get to know him more herself, but there's one problem.. He doesn't talk. Of course, Undertale belongs to Toby Fox, not me lol

(Finished!) Anyways here's the plot (Grammar is also junky) This is a nightmare sans X Fem! Reader Just to clarify, I drew '(Y/n)' in the way I imagined her to sorta look like. She does not actually look like that it's just me. You're a girl (just roll with it) who is 22 years old and you have earthly powers, (more will be explained about the powers) Your father wanted a boy instead of you and he left your mother when you were born. Chasing after another woman your father was no where in sight. Your mom found out later that he was murdered by his new wife for his money and there your mother was left a widow to care for her only daughter. At 10 she died and instead of going to an orphanage, you took care and lived in your mothers small cabin deep in the forest with a small garden of course. You always heard of the guardians who guarded the tree of feelings and for the townspeople they always spoke harshly about the one they call Nightmare. Rather Dream, he was worshipped and praised for protecting good and positive feelings. And Nightmare protected the negative ones which of course they did not want. You on the other hand saw that without sadness and loss the world would be out of balance. So you always thought of Nightmare as misunderstood. And owning a small flower shop in the town you made two baskets full of sweets, flowers, and bread, thinking of how it would be a nice thank you gift for the two guardians who protected their respectable feelings. But what you didn't know was with that simple gesture of kindness, a certain skeleton became very interested in you. This book will have you wear dresses and nightmare will of course wear clothing suitable close to the Middle Ages, so basically it's kinda like back then. There are most likely going to be errors in the grammar so please excuse them (Artwork by me) I hope you enjoy this! (Also please keep in mind that I will most likely draw the outfits + maybe some parts of the book)

One clumsy moment and a broken leg are all it takes to leave you at the mercy of the very edgy and very hostile monsters of the underground. Thanks to your knowledge as a doctor (and oath to do no harm), you're able to convince the Great and Terrible Papyrus to keep you alive. But how are you going to find your way back to the surface with a bum leg and a short skeleton that doesn't seem to like you? | - UnderFell Sans x Human Reader - Enemies to lovers but Fell is the only one hating - Your leg privileges are revoked, and Fell needs to wash his mouth with soap - Flowey is an equippable companion and decides to help you cuz he actually gets something out of it - My own interpretation of UnderFell (tho from what I've seen it doesn't really have a narrative anyway)

Gone. In a single moment, in the blink of an eye, everything you have ever known or cared for is eradicated. Hopes and dreams, traditions and stories that date back centuries have been erased without thought or care. Nothing matters and no one will ever live again to pass on the memories and stories of what was lost. Except you. You are the anomaly, the glitch that survived when all else could not. When your universe was destroyed, you found yourself stranded, alone, afraid in a white world without end. But there's little time to rest when you discover that your universe was merely a grain of sand on a much bigger ocean. Whole other worlds thrive in different plains of existence, and they're all going to war. In a desperate power-struggle for the upper hand, you find yourself an unlikely ally. The future seems certain, chaos will win and the universe will be plunged forever into violence and bloodshed. And it will take a lot more than a miracle to win.

Want to talk about falling into the wrong place at the wrong time? Y/N definitely scored big time on that one. One moment she's falling, the next she finds herself trapped underground with a monster that wiped out his own kind. He's a cold-blooded killer that never shows any emotion. Though, as time passes, she finds out that Sans isn't as heartless as he plays himself to be. Hello! Writer~San here! Cover art and Undertale AU/Characters aren't mine, but the story definitely is. I hope you enjoy it!!!!