"North by Northwest"- Suspense depends on editing.

As we know, it is famous for Hitchcock’s interview about Bomb which suspense creates when audience see a bomb under the table in the condition that a protagonist doesn’t know the fact and the time of the explosion comes. Based on this perspective, his “North by Northwest” has the outstanding suspense. The notable thing is that he controls the level of suspense by using editing relevant to each situation. In other word, I think suspense of this movie is very correlated to editing.
First, the short duration of editing in the beginning multiplies suspense. A bomb which some people kidnap and kill the protagonist explodes in the opening of the movie. And then audience questions himself like this ‘Why do they consider him as Kaplan and What happens next?’. Hitchcock shows the introduction from the start to the his escape being wrongly accused of the murder with very rapid transition of shots. Therefore, it is never boring for audience to follow the story until the bomb explodes.
Second, the editing between the protagonist and Kendall makes the tense tempo relieve even though he is in danger. Uniquely, whenever the director shows two people, fall in love each other soon, he always designs the relationship and mood by repeated 45º angled shot/ reverse shot.
Because shot/ reverse shot has identical size, eyelevel and symmetrical direction, we feel easily affection to become deeper between them and can deviate from suspense for a while.
Third, the scene chased by plane enhances thrill by doing eyeline match through POV.
The protagonist stands on the wide road. He looks around to find someone to be scheduled to meet. The shots in this scene consist of him and surroundings which he sees. This tells audience where he is and makes running him follow easily after the advent of plane.
In the end of this scene, fast transition between POV of protagonist and plane flying toward him reinforces the suspense.
At last, the movie keeps thrill until ending by suggesting the parallel editing between two people (protagonist and his lover) and the villains chasing them.
The continuous shots chasing and chased of two groups at the same time and space, at the sharp top of Mt. Rushmore, make us feel suspense by instinct even if we guess the happy ending.
As mentioned above, suspense depends on how the editing arranges and composes the shots.
Although we get ourselves absorbed in the narrative and acting of the cinema and cannot help grasping the compositions of shots easily, editing takes a essential role to show many feeling including suspense.