The Bomb Under the Table

Hitchcock's philosophy was simple: if two people sit at a table and a bomb explodes, you get surprise. If the audience sees the bomb but the characters do not, you get suspense. Surprise lasts seconds. Suspense can last an entire film. This distinction became the foundation of thriller filmmaking.

He demonstrated this in film after film. Rear Window traps the audience in a wheelchair with Jimmy Stewart, watching a possible murder unfold across a courtyard. Vertigo tells you the twist two-thirds through and becomes more suspenseful, not less.