Das Retreat

The story took its time setting up the characters and setting, but I kept waiting for the tension to really ramp up. Was the pacing in the beginning intentional to build suspense?

The isolated location added to the suspense, but I'm curious if the author had a specific reason for choosing this environment or if it evolved during writing.

Some clues felt pretty obvious to me, but I wonder if others picked up on the hints before they were revealed. Did the author intentionally plant red herrings?