In the Underground, 19XX. The Underground has been always the same, being a complicated network of crime infested cities. there, a woman named Frisk is just taking a stroll around the Underground. Frisk was just a small thief who break into The Underworld with the help of a distant family friend, toriel. She is certain that that she is going to rule the area with an iron fist someday. She just have to take the mafia bosses first.