In the end, I felt like the mystery still left me hanging. There's really no plot. Like all the other games in this series, there's a crazy psychopath 'out there' with very serious hallucinations in his head.
Oh yes, let's not forget that there's always a youtube walkthrough in case you get stuck. I confess that I consulted it once.
I've got 3 more of these games to play. Saving them for a rainy day.