You are walking around Snowdin (after falling into the hole of Mt.Ebott and exploring the Underground.) and see many monsters but no humans around as far as your eye can see. You then see someone at someone else's house, "A human, like me, finally." You say in your head as you walk over to them, they look like a girl and tall too. She carries the blank expression when she turn around to meet you.

Frisk: ". . . W-who are you?"