Surface Truths » by VeryPeeved A kid falls down a vast chasm into the deep, and is set upon by countless monsters eager to murder whoever falls down and claim their souls. Somehow, this child is the villain in your story.

River Flows » by SbOcean The Riverperson is a very mysterious person in the Underground. Letting Frisk ride in their boat wherever they need it. They are always so carefree, but what if there is more underneath the surface.

167One World, Many Souls » by Halloween Witch With a quick use of Sans' magic, we had returned to our home on the surface. The lovely three-story home sat quietly among the trees under the moonlight. Sans always loved to teleport just outside the door and glance at it before walking in. He was a little less lazy since coming to the surface. So much to learn. So much to do. So much to love. SEQUEL TO "TWO WORLDS, TWO SOULS"

29Absolution » by aziuka Sans is putting himself through hell - not knowing that there's someone out there who wants to save him. Based on the Dusttale AU.

1k+DoubleTale: Rewritten » by XWolf26 What if two humans were in the Underground at once? What if one human was DETERMINED to stop the other? What if they could both SAVE? What happens when an Unstoppable Force meets an Immovable Object? When a certain scientist pulls enough of himself together, he finally finds a way to stop the destruction of his world. (Undertale AU. Rewrite of DT.)

7The Lost Soul » by Ulrich362 The power to reset the timeline, and the determination to move forward no matter what the cost. These are the two things that keep a young girl moving forward in the mysterious world of the underground. She could be the key to their salvation, but would it all be worth it? Especially if the one person that matters most remains trapped and alone. (I don't own Undertale.)

1Hopetale: Enter Underverse » by Papermarioknight4178 Frisk and Chara were supposedly just average kids, living in a world where the human monster war never happened. However, when they find out about alternate universe, it is a literal race against time, to save not just their world, but others too.

Let's Do the Mortal Coil Shuffle » by Taliax A "shortcut" gone wrong results in Sans and Papyrus swapping bodies. But the greatest scientific breakthroughs often start as accidents—and this might be the key Alphys needs to save Chara and Flowey. (Includes Soriel, Papyton, and Alphyne as ships. Crossposted from AO3)

Shady Tale: The Beginning » by ShadyNexus Frisk is a 18 year-old young man who just graduated high school. He arranges a hiking trip with his best friend Jack, which leads to him falling in a mysterious hole. Can Frisk survive the monster realm?

The Echo that once was by Miguel16310 Reminiscing about the past should always be about laughs, nostalgia and joy, sometimes sadness. Atleast, that's what Asriel Dreemurr used to think, before his sister ended up shaking him to his core. To Chara, her brother is going insane. Perhaps it's the truth... but when you can't trust your own memories, then who can you trust?

Shattered Hopes by NoobiePro1234 Frisk woke up. What had happened? They soon found out they were not in control of their body. More to their dismay, the one controlling them wasn't a very merciful person. If Frisk doesn't get control back, who knew what would happen to the Underground? They would soon find out…

47 Divine Soul - Genesis » by Myu98 A single choice has a huge impact. Not just on one person's life, but on everyone around them. In the Underground, there are many paths one can take. But when Frisk makes a choice that takes them off all the known paths, the world is changed forever, and Frisk becomes intrinsic to the fate of not just Monsters, but the whole world.