I think there is should be a way to reduce influence of luck for repetition of this dream
My suggestions is
1) reduce the price of solving mysteries for 2nd and later visit.
2) Allow to resolve mystery from any space of the tile there Denizens are.
Because of this dream is kinda easy fully exploring it the way it is might take too many attempts and become really boring, so we made this adjustments for our 2nd and 3rd visits and we were happy with it.