"Double Exposure" is one of my favorite episodes. Up until the very end, it seems Columbo has finally met his match, facing an adversary his equal in both intelligence and observational powers. So it pains me greatly to report that I think I may've found a gaping hole right in the middle of the plot (WARNING: spoiler).

If you've seen this episode, you already know the importance of The Missing Nickel:

The projectionist, who winds up murdered, tells Columbo he always sticks a nickel into the reel of whatever film he's projecting so that when the nickel falls to the floor he'll know it's time to change reels. But when Columbo shows up at the murder scene, he notices there's no nickel on the floor, so he figures somebody else changed the reel. Since the murderer's alibi hinges on the projectionist still being alive at the time the reel was changed, Columbo isn't thrown off the trail as planned and goes on to solve whodunnit.

Ah! Okay, fine...but there's just one more thing, sir, and here's what's troubling me...

Why WASN'T the nickel on the floor? The projector was running at the time of the murder, which means the projectionist had already loaded a reel -- complete with nickel tucked into it. No matter who loaded the next reel, the nickel from the replaced reel still should've fallen to the floor!

The murderer certainly wouldn't have taken it -- why would he? In the first place, it didn't tie him in any way to the crime scene, and secondly, having an intimate knowledge of the mechanics of projecting, he would've known what the nickel was for and that his alibi would be ruined if he removed it.

So whaddya think, sir or madam -- am I missing something, or did the writers make a rare flub?

Interesting observation. It seems like an open possibility to me, as we don't know who loaded the second reel. The projectionist might have already done so, in which case, the nickel would fall. However, he might not have done it yet, in which case Kepple would have had to load the reel and then make the switch..no nickel.

The impression I got when the projectionist explained his system to Columbo was that he stuck a nickel into the reel either just before or right after loading it -- at any rate, the nickel would have to be in there before the reel actually started turning, right? So, since there's no doubt the reel that was playing when the murder was committed had been loaded by the projectionist, the nickel must've been in there, and would've fallen to the floor (where Columbo would've spotted it) no matter who loaded the next reel.

Ah yes I thought that as well, but also how would the projectist hear the coin fall with the projector making so much noise.I think it was said that "their was no nickel under two projector" but surely the nickel had it been placed in the film in the first place would have fallen under Number one projector, or am I being to picky. This is still a good episode, especially the golf game scene, and when Columbo trys to trap Keppell about where the threatre was, left or right I think was the question from Keppel,Columbo only to reply, "you can't win em all".

D'OH! I get it now -- the coin was missing under the SECOND projector! That's what blew the alibi (although the more I think about it, the less I understand how Kepple's alibi was supposed to work in the first place... but maybe I better save that for a new thread).

Obviously, I ain't no Columbo...

The whole "alibi" is spurious, thus ruining the episode for me. Nickel or not, someone ought to have been at the Magnolia to change reels. Certainly it was not the dead operator, but it couldn't have been Keppel either, since that reel change is supposed to have happened at a time (07:30pm)when Keppel was in his studio with Columbo!