He starts walking in a snowy place covered with woods. When he is walking a branch breaks mysteriously and he hears some steps. When he arrives to a tiny bridge closed by wide wooden bars someone in shadows begins to get close.And asks him if he knows how to greet.He turns around and shakes his hand and fart noises begins.He introduces himself."Sans, Sans the skeleton.you are a human right.Huh that's hilarious".He seems goofy and takes frisk to his sentry station.He hides Frisk because he wants to make his brother happy .Then his brother-Papyrus- arrives.