A Bomb Under the Table

In 1962 François Truffaut, then a young critic turned director, sat down with Alfred Hitchcock for a week of interviews that became one of the most useful books ever written about making films. Early on, Hitchcock explained the difference between suspense and surprise, and he did it with a bomb.

Imagine two people having a dull conversation at a table, he said. Suddenly a bomb under the table explodes. The audience gets a surprise: a few seconds of shock. Now imagine the same scene, but the audience has been shown the bomb being placed, and a clock on the wall says it will go off in fifteen minutes. The same dull conversation becomes unbearable. People in the audience want to shout at the characters to stop chatting about baseball and look under the table. You have exchanged a few seconds of surprise for a quarter of an hour of suspense, and all it cost was information.

That is the whole theory, and it is almost embarrassingly simple. Suspense is the gap between what the audience knows and what the characters know. Hitchcock spent half a century finding new ways to open that gap.

He had a matching idea about plot, which he called the MacGuffin. In a spy film, it is the secret plans, the stolen formula, the thing everybody is chasing. The characters must care about it desperately. The audience barely needs to know what it is. Hitchcock liked to illustrate this with a shaggy-dog joke about a device for trapping lions in the Scottish Highlands, where there are no lions, and the joke is the point: the MacGuffin is nothing, a pretext, and the film is about what people do while they chase it.

Psycho (1960) turned both ideas inside out. For forty minutes the audience follows Marion Crane and the stolen money in her car, the money being a perfect MacGuffin. Then, in the shower at the Bates Motel, the film kills her. The scene took about a week to shoot, from something like 78 camera set-ups cut into some 50 shots, by the usual count, for well under a minute of the attack itself. The film was black and white, so the blood was chocolate syrup. The knife is never seen entering the body. The cutting makes you believe you saw it, which is Kuleshov's lesson with a blade. Hitchcock had originally wanted the scene to play without music. Bernard Herrmann wrote the shrieking strings anyway, and Hitchcock, once he had heard them, changed his mind.

Hitchcock liked to say that his films were finished before shooting began, because every shot had been worked out on paper, and that the shoot itself bored him. It was partly a pose, a story he enjoyed telling, but the storyboards were real, and they left actors little room. A Hitchcock performer was a component in a design: told where to look, how fast to turn, which half of the face to give the camera. He made a joke about actors and cattle and went on making it for years. Some actors loved the precision. Others found it chilly.

His audiences loved him for the cameos. From The Lodger in 1927, he turned up briefly in most of his own films: carrying a double bass, missing a bus, appearing in a newspaper advertisement in Lifeboat, where there was no room for him on screen. They became a game, and he was careful to place them early so that people stopped hunting and watched the film.

There is a darker part of the record, and it belongs in any honest account. Tippi Hedren, whom he cast in The Birds (1963) and Marnie (1964), later said that he made repeated unwanted advances, that he assaulted her, and that when she refused him he kept her under contract and stopped her from working elsewhere. The account appeared in Donald Spoto's biography and, in her own words, in her 2016 memoir. Hitchcock died in 1980 and never answered it. The control that made his storyboards so exact is not a separate thing from what she describes, and it is worth holding both in mind.

The bomb under the table is still ticking in nearly every thriller made since. It is good to know whose hand placed it, and what else that hand did.