In 1957, MGM had the rights to a Hammond Innes novel called The Wreck of Mary Deere, a kind of Caine Mutiny property involving trouble at sea and big courtroom scenes, that they wanted Alfred Hitchcock to direct. Hitch agreed he needed a writer. Bernard Herrmann, the composer, already signed up to score the picture, suggested Ernie Lehman, an MGM contract writer who just had a hit with Sabrina. So Hitch and Lehman met to discuss the project, but Lehman wasn’t keen. It just wasn’t his type of story. But the two men liked each other’s company, so they kept talking, meeting each morning at Hitch’s house. But it eventually became clear that Hitch wasn’t too keen on the story either, because every time Lehman brought up Mary Deere, he’d change the subject. After about three weeks of this, Lehman threw up his hands and declared, “Look. I don’t know how to write this picture. I quit.” And Hitch said calmly, “Don’t be silly, Ernie. We’ll write something else.” So they wrote North by Northwest instead. Although it was a long, tough road. Neither of them had a strong idea for a picture at first, except that Hitch had collected in his imagination a grab-bag of scenes and images he would love to see filmed: a new car comes off the assembly line with a corpse in the boot; a delegate is murdered during a meeting of the UN Security Council; an Eskimo discovers a body in his ice-fishing hole; a hero is lured to a desolate place by villains who try to run him down with their car; a little girl finds a gun in a baby carriage and shoots someone; a man is chased across the presidential faces of Mt Rushmore. And there were plenty of others, vivid vignettes that Lehman knowing how the hell he could turn them into a coherent story. All he knew was that it would be a chase movie, a ‘wrong man’ movie like The 39 Steps, and, since the scenes seemed to stretch across the continent from New York to Alaska, he gave it the working title In a Northwesterly Direction. When Hitch took off to the Bahamas for a holiday that summer, Lehman took a few field trips to pick up some location colour. He visited the UN headquarters in New York, met with a retired judge from Long Island who went through the procedure for booking and arraigning a drunk driver, took a trip on the Twentieth Century Limited to Chicago, and checked-in to the Ambassador East Hotel. He even convinced a forest ranger to take him on a scramble up the side of Mt Rushmore, until he realised that this was a stupidly dangerous occupation for a screenwriter with no head for heights. By the time he sat down to write, Lehman had more of an itinerary than a plot. He didn’t know how he was going to get his characters from one place to another. It was torture. He called the writing method “painting yourself into corners”: you have a hero, you drop him into trouble, then think up a way to get him out of trouble. Then you drop him into new trouble and find a way to get him out of that. You do it again and again, one step at a time, constantly asking, ‘Now what?’ At one stage late in the writing, he had all the characters at Mt Rushmore and he was really stuck. Stuck for days. Why were they there? What happened next? In desperation he phoned Hitch and they met to nut out a solution, but they just stared at each other. Blank. But the subconscious machinery must have been whirring because, after a few hours, while Hitch was talking about something else, Lehman blurted out: “She takes a gun out of her purse and shoots him.” Hitch took it in his stride: “And the bullets are blanks.” Within a few minutes of back and forth, the entire ending of the picture was sketched out, and within a few weeks the draft was completed. The auteur theory of filmmaking says that Hitchcock was the only and true author of North by Northwest, but a look through the original screenplay puts that in serious doubt. The final picture is there. Lehman wrote very specific descriptions of shots and more than ninety per cent of them appear in the final film. Nor is Hitchcock responsible for the quality that has made North by Northwest a perennial favourite: its lightness. That’s mainly Lehman. There is a particularly flippant tone in the writing, which helps smooth out the bumpier stretchers of the plot. It’s quite distinct from the macabre ironies and sexual suggestiveness characteristic of Hitchcock’s wit. No matter how deeply Thornhill gets into trouble, he never loses his charm. Of course, it helped that Thornhill was played by Cary Grant, who perfected breezy insouciance for the screen. Yet you have to admire the way Lehman, while pulling out his hair over the improbable plotting, still found a way to convincingly transform the glib, womanising advertising executive of the first scene into the hero of the finale who would risk his life for love. Like Grant’s characterisation of Thornhill, the Lehman screenplay revealed grace under pressure.