Ever heard of Chekhov's gun? It's a those-in-the-know literary term for the idea that, if you see a gun in the first act of a story, it's gonna go off in the third.

We've got a bit of a Chekhov's gun situation here in Die Hard, although we don't have to wait until the third act to hear it go off. We see McClane's gun in the very first scene of the movie, when his seatmate spots it poking out of his jacket and is understandably alarmed. We have to wait a long twenty minutes or so for that gun to go off, but once it does, all hell breaks loose. Guns, guns, everywhere. And his Beretta gets plenty of action.

But it's the last shot that counts.

McClane's Best Friend

John McClane's sidearm is with him throughout the entire movie. Sure, he hands it to Hans for a brief moment (but he's removed the bullets, so it's all good). And sure, McClane sets it aside on occasion in favor of the occasional machine gun, but it's clear that his Beretta is as trusty a sidekick as Sergeant Al Powell.

Once we see McClane's sidearm on the airplane, we'd be foolish not to notice the foreshadowing. But as the movie progresses and we see that McClane is going to be firing his weapon quite a bit, what we're really waiting for is the most significant shot of all: the showdown with Hans Gruber at movie's end.

McClane's only got two bullets left, and, as luck would have it, two bad guys to take down. But he knows he can't just waltz in there and blow them away—both Hans and his henchmen are armed, after all, plus, they've got Holly. So McClane cleverly tapes his loaded Beretta to his back as a ruse to make Hans think he's got the upper hand. And what do you know? It works. (For more on this, check out "What's Up With the Ending?")

Why Does All This Matter?

Because McClane's gun is basically McClane, in gun form.

Allow us to explain. A Beretta 92F is a perfectly fine weapon. We're sure it serves John very well in the NYPD. But it's no rocket launcher. Much as John is no match for Gruber's well-oiled crime machine, his Beretta is no match for all the crazy weapons that Gruber brings to the party. Basically, he brought a handgun to a warzone.

And yet.

Both McClane and his sidearm get the best of the bad guys precisely because they're both so underestimated. In the climactic scene, Gruber thinks he's got the drop on McClane as soon as he makes McClane put down his big, scary machine gun. But little does he know, McClane's got his trusty Beretta—with just enough bullets of course—to get the job done, once and for all. The lesson here? Sometimes all it takes is an everyman, with his everyman weapon, to slay the suave dragon. Underestimate McClane at your own peril.