If this is the fifth installment or chapter, it represents the "Point of No Return." The characters have gathered enough history to feel the weight of what they are losing, but they aren't yet at the resolution.
Rain blurs the lines between tears and water. It allows a character to cry without being seen, masking their vulnerability. 5 : A Parting in the Rain
The "hiss" of rain creates a private world for the two people parting. It drowns out the rest of society, making their final words feel like a secret. If this is the fifth installment or chapter,