For those who are unfamiliar with the term, the word “macguffin” was popularized by the late Alfred Hitchcock, and refers to a specific, inanimate object within a movie that exists solely to advance the story. As an example, Hitch himself liked to point out his own film "Notorious.’ (note: since all the following examples I cite are pretty well-known bits of film lore, I’m going to feel free to dispense with spoiler boxes.)
In “Notorious” : a cartel of South American based nazis are smuggling uranium in wine bottles. Why are they doing this? Where did they get the uranium? and to whom are they smuggling it? Hitch gleefully admitted that there are no rational answers to these questions. But the screenplay dictated that Ingrid Bergman’s character must infiltrate the nazi cartel in order to find out what they were up to. (and eventually become endangered, so that she can ultimately be rescued by Cary Grant.) Therefore, the nazi’s had to be up to something! They couldn’t just be sitting around playing cards and having gala parties. Smuggling uranium in wine bottles seemed as good a reason as any!
The sled Rosebud in “Citizen Kane” is another famous example. There is no reason given within the film why Kane should cherish the memory of this sled so much. But Kane has to cry out for something from his youth, something he would have had to give up as he became an adult. (and crying out “mommy” on his deathbed might have been a bit too obvious, and probably wouldn’t have inspired any in-depth investigation into his past.) The sled, in itself, doesn’t matter much. It’s importance within the story however is monumental.
And then there’s “Belle Du Jour.” In one famous scene, a “john” shows up at the brothel with a small wooden box. The box contains an object he has a fetish for and wants to use with one of the hookers. He shows it to one “professional” hooker, who shudders and flat out refuses to use it. Catherine Deneuve’s housewife hooker (who’s supposedly slumming for cheap thrills) IS willing to use it, even though it does make her nervous. After her tryst, Deneuve seems to have actually enjoyed it. We never know what actually was in that box, just that it was something so extreme that the jaded “pro” hooker wouldn’t touch it, but Deneuve would. It shows just how deep her erotic desires actually run.
So, the uranium-in-the-wine-bottles, the Rosebud sled, and the mysterious fetish-object-in-a-box are probably the three most famous “macgufffins” in film history. It seems that there has been a derth of interesting macguffins in movies over the last few years. I’m just trying to think of some others.
(BTW, as a side note, the unknown object in the box in “Belle Du Jour” is supposedly the inspiration for Marsellus’ mysterious briefcase in “Pulp Fiction.”)