One of the keys to the brilliance of the film is the way the director tells the story, also known as narration. There are two basic forms of narration in film, omniscient and restricted. In many, perhaps the majority of films, omniscient narration is used whereby the viewer knows everything that is happening in the story. Inevitably however, this will be more than the characters know, each of whom have a restricted view of events, just as we do in real life. While this may sounds dull at first glance, having complete knowledge creates suspense - how and when will events unfold? By contrast, restricted narration (of which there are infinite levels) often puts us in the shoes of one of the characters. Because we don't know what's going on either, this makes for mystery, confusion and intrigue.

A winning combination
In North by Northwest, Hitchcock uses a combination of these two forms of narration to tell what is a relatively complex plot. For the first 40 minutes the viewer is, to all intents and purposes, Roger Thornhill, and as such has no idea who George Kaplan is and what Vandamm wants from him. Thus we have our first example of intrigue, something which is maintained right up until it is revelaed that Kaplan is in fact a non-existent decoy, invented by the government to ensnare Vandamm. But while we now know more than Thornhill, it doesn't really explain anything.

The next shift in tone occurs when we see Eve sending a note to Vandamm. Suddenly, suspense is added to intrigue - what was blissful ignorance turns to concern for Thornhill and suspicion of Eve's intentions. Who is she? Why is she working for Vandamm? And why are the government concerned about him? So even as the layers are unravelled, we are kept engaged.

The iconic crop duster scene
Halfway through the film, comes a truly iconic scene. By now we know that Eve is not to be trusted so when she sets up a meeting with Kaplan for Thornhill, while he is eager to find out who this mystery man is, we can only suspect that this isn't going to end well for Thornhill.

Thornhill arrives at the supposed rendezvous point, a desolate spot to say the least. Hitch treats us to a sumptuous establishing shot from high above the road which not only looks great but also shows our hero's isolation. For the next minutes, there is virtually no dialogue, merely a series of beautifully crafted establishing and point of view shots. These typify the director's grasp of not only technique but also suspense. The longer nothing happens, the more tense the sequence becomes until it suddenly bursts into life with the aerial arrival of the crop duster bi-plane. It's a wonderful scene and we learn that these people will stop at nothing to get rid of Thornhill.

As we enter the final act, two more pieces of information are revealed. First, we discover that Eve is Vandamm's lover, something which changes the dynamic of the relationship between her and Thornhill. Shortly after this, there's an even more dramatic shift as we find out that Eve is in fact an undercover agent and the best way Thornhill can help her is by cooperating with the Professor. Even at this late stage, the narration remains partially restricted and so there is still intrigue. but now, the tension is even more meaningful as Thornhill's emotional investment in Eve has been reignited.

A masterclass
That the final twists and turns still feels plausible are a credit not only to the well-constructed plot but also to Hitchcock's direction. This isn't simply a matter of throwing a few big set pieces together and hoping for the best. Each scene works because it concentrates on progressing the story and revealing character. Everything is there for a reason, nothing is mere padding or whimsy. It is a masterclass in storytelling and filmmaking.