Reader/Sans. A run-in with a human mafia sets you on a path pulling you ever closer to Sans- a laid-back skeletal monster mobster with a knack for giving you goosebumps in more ways than one. Drawn to one another in an era of danger, intrigue, and the Prohibition of magical food & drink, you find yourself irrevocably tangled in the darkest workings of the shadows of Ebott City.

When fate prevents a younger Frisk from ever falling into the depths of Mount Ebott, 15 years pass before they're able to venture close again. What has happened to the monsters in those years? Thorny vines now prevent even most magical approaches to the mountain, and rumor abounds about the fate of the monsters trapped inside. Something isn't right, and Frisk is about to find out.