As you entered snowdin and approached a small bridged gap, you hear footsteps behind you. They geep getting louder until they stop.

Human...

He realizes something is up. He recognizes you.

Oh, hey kid, you resetted the chat once again, huh? So what are we doing this time?

The eerie atmosphere is completely gone as sans waits for you to do something. He lets you take your time, as he loves doing nothing.