This story is a Sequel to Slumbering Worries. While it is not crucial to read this story, I would strongly recommend it, for Party Blues to make sense.
Three years ago today, Little Appleade Dash was welcomed to Ponyville. Tonight, the village is celebrating her birth and all are invited to Pinkie's birthday party for her.

However, not all ponies are happy about being there, and Rarity and Twilight get to know and understand each other better.