Alfred Hitchcock understood the essential difference between mystery and suspense.
There’s a great deal of confusion around mystery and suspense. They’re often tossed around in the same pitch meeting or over script notes. But the two are not analogous. The two are absolutely miles apart.
Mystery is an intellectual process while suspense is essentially an emotional process. You can only get suspense going by giving the audience more information than the characters.
For Hitchcock, films that have mysterious goings-on where you don’t know what’s happening or why someone is doing this or that, are a waste of time and footage. There’s no emotion, no feeling.
A twist or revelation with no emotion is shallow indeed. Mystique and mystification may seem an appealing strategy to keep an audience interested but have the opposite effect.
Because when you mystify an audience, you don’t hold them.
You lose them.