Every story needs a starting point, a thing for our characters to want, a goal to pursue. These wants can be as varied as true love, fame and fortune, the identity of the myysterious killer, and on and on. In some stories, however, the thing the characters seek, is well...nothing at all.

Well, it exists, but its existence is, in the words of Alfred Hitchcock, "nonexistent." If this sounds confusing, it's because the thing we are seeking is the elusive MacGuffin, a term coined by the master of suspense and explained in the below video from Fandor. Check it out, and read more about the MacGuffin below. 

The rabbit's foot in Mission Impossible III is a fine example of a MacGuffin. As the video explains, Ethan Hunt spends the movie in pursuit of this lucky charm (actually a canister of some kind,) the characters discuss it to no end, and the success or failure of the impossible mission is predicated on its retrieval. At the end, however, neither we, nor Hunt, know what was contained inside. It was simply there to drive the plot forward.

Another famous MacGuffin is the briefcase in Pulp Fiction, functioning slightly differently. While possession of the mysterious attache and its glowing contents drive part of the plot, in this case the characters do know what's inside; it's the audience that's left in the dark, fan theories notwithstanding. It's still a MacGuffin, though, because even though it's not important that the audience know what's inside, it is vitally important that the characters wantit

"Here, you see, the MacGuffin has been boiled down to its purest expression: nothing at all!"-Alfred Hitchcock

There are countless examples of MacGuffins out there, but what they all have in common is that, despite being concrete objects, none has any real function other than to be desired (and in doing so, move the story along.) This means, however, that not every object pursued is a MacGuffin. Rosebud in Citizen Kane, for instance, is not a MacGuffin, because not only does it actually means a great deal to Charles Foster Kane, but its nature is revealed at the end. A true MacGuffin is there but not there, full of meaning and yet totally absurd. 

Hitchcock himself said that his best MacGuffin, the "emptiest, the most nonexistent, and the most absurd" appeared in his classic North by Northwest.  At the end of the film, we learn that the spies have been chasing "government secrets," though that's all we, or Cary Grant, ever find out. Any importance these secrets might have is utterly inconsequential to the plot, and it's this, in Hitchcock's opinion, that makes it the most MacGuffin of all MacGuffins, i.e. the one "boiled down to its purest expression: nothing at all!"

The important thing about the MacGuffin is that it gets the characters out of bed, as it were, and off to the races. Which, paradoxically, might make the MacGuffin the most important thing in the movie; after all, without it, there wouldn't be a story to tell. 

Source: Fandor