I recently finished reading the ritual and was thoroughly emotionally exhausted by the time I got to the last few pages ! Adam Nevill is a brilliant storyteller and thankfully he doesn't use any gratuitous gore to get his point across, the brilliant thing about this story is that it is set in the mundane world of the ordinary, a group of mates on a walking holiday and then the strangeness starts.
I could not have second-guessed this story even though I thought I had, the surprises and the shocks just kept coming!
I intend to read all of his other works, highly recommended !!