Suspense is the build up to a big event. In order to create suspense you must be able to engage the audience through various things such as scary music, tension and visceral effects etc. One of the most famous theory's is the 'Bomb Theory' by Hitchcock. This is when the audience is aware of an event or object whereas the characters don't. Moreover, false plateau's are often used to relax the audience for a better effect when the event occurs.