The place where it rained

The 70th track in the Deltarune chapter 3+4 ost, which is a rendition of the song It's raining somewhere else from Undertale but without the sans motif. It's a very melancholic song likewise its predecessor, which plays after Kris and Susie exit the the church's dark world and the reveal of the final prophecy. It is a very impactful song principally if you have played Undertale before, usually giving the player a nostalgia attack. Because it lacks the sans motif, and considering how happy he is in the "jitterbug" sequence, it is a common theory that this song is actually a prequel to its raining somewhere else which would be consequence be sans reminiscing about the events that happened in Deltarune's hometown, therefore that being the place where it rained.