The Master of Suspense Alfred Hitchcock was often related and confronted with a widely common phrase: "Whodunit?" ...and, though his various explanations about an idea, that he called the MacGuffin, a technique to push the story forward while in equal amount increasing tension, he was never associated with: "Whatsinit?" - How come?
Maybe even Hitch underrates the power of well crafted MacGuffins, as he once said:
„(The MacGuffin)... is a thing that the spies are after but the audience don't care.“
Right, sometimes a MacGuffin is actually forgotten by the end of the story, but the one in „Pulp Fiction“ stands the test of time. The audience is not willing to forget - even after decades.
So Whatsinit? A white sheet of paper and a light bulb?
The soul of Marsellus Wallace? Gold? Diamonds? An Academy Award for Best Original Script? Yeah, maybe. But in each and every case the rich imagination of an active viewer.
Whatever it may be that is projected by the audience is definitely mystery – no misery.
What if the mystery was unravelled, what would we gain by knowing and what would be lost?
Anyway, the briefcase offers space to participate & interact with a finished movie, enables us to put additional content between the double spaced typed lines of a masterful crafted screenplay, that requires no addition at all and yet it does.
Thus the briefcase is a placeholder that also includes one the best „Contradictio in adiecto“ in cinematic history.
Just to add to the richness of imagination by the active viewer I have always liked the idea that the briefcase holds a gun that was given Mrs. Wallace by Mr. Wallace instead of a wedding band or such.
When Vincent opens the case one can see that it was made by FRANZEN. This company is known for manufacturing dust bin locks, Rat- and Mousetraps („Yeah, the spider just caught a couple of flies“), Trigger-Key-Locks and Gun-Cases.
So therefore there´s a chance it holds a gun.
Further when looking at the original movie poster we see the mistress on a mattress with a novel, cigarettes and a gun.
So she got one and it might been taken away from..... well, I don´t care if this is true or not, I don´t want a solution. It is just my personal point of view to contribute and to join in the fun of discussing the topic.
Quentin once said: „If a million people see my movie, I hope they see a million different movies.“ Well, QT, they did.
Guess, this case will never be closed – it is being opened every time Pulp Fiction is watched.