Understay - an Undertale Fanfic

An alternate universe of Undertale, in which Frisk decides to stay underground for the rest of his days.
DISCLAIMER: As well as the usual "I don't own Undertale or its content" spiel, I also make a few assumptions as to how the game goes.
Frisk is male, and an old child - pre-teens.
The run is a neutral run; although Frisk hasn't harmed anybody, he wasn't aware of the possibility of dating Alphys, and so is unaware of the True Lab.
This story contains spoilers for all three endings!

Cover art provided by Serain, who can be found at http://serain.deviantart.com/