Opening Scenes and Enigma - Introduction

The third convention that I've noticed in opening sequences that I'm going to be looking at is the creation of enigma/mystery. I'm going to be looking at two opening sequences that introduce enigma/mystery. The first film that I'm going to be looking at that introduces enigma /mystery is 'Rebecca'.

The second film I'm going to look at that creates enigma/mystery in the opening sequence is 'Psycho'.