Datamining spoilers. Huge spoilers:
Dataminers have found text in the code that someone in the grove is working for the Absolute and the refugees are being marched into the hands of the True Souls. This may or may not be an early draft of the plot that was abandoned.
Someone more perceptive than I noticed that the song at the party is a variation on the harpy's song. Suggesting that the party is part of an effort to lull everyone into a false sense of security.
And then there's that note in the bottle . . .
