So I don't know if you folks saw this or interpretated this in the way I did. But I think the events which unfold after Jack's return party foreshadow everything wrong that is going to happen. When the gang is done singing and partying that night, it starts raining with full on thunder. Dutch gives a loud motivational speech on "TAHITI, AUSTRALIA" and about being free. Then he can be seen arguing with Molly. Micah gives a speech on survival or something like that. Bill punches Pearson and Kieran disappears the next morning.
All of a sudden, the scene of the camp changes from the positive party-like atmosphere because of Jack's return to a silent, negative and unsettling atmosphere with all that rain pouring and the sound of lightning in the background. It is a beautiful piece of imagery, but the foreshadowing is unreal.
Who else thought the same?