A hold shelf mystery:

so I go to retrieve a book from our Hold Shelf for a patron who had recalled it, and when I get back to the front desk she takes a look at the title and says, "That's not it." Sure enough, it's not. While the automatically-generated slip has her contact information and the reference that she was in fact looking for, it had accidentally been paired with the wrong book, which presumably was misfiled under another patron's name. As going back to the Hold Shelf and looking for the book blind is not an option here at Widener, since the "shelf" in question is actually a small set of stacks with hundreds or thousand books on any given day, there was only one chance for finding this patron's book - finding out who the wrong book was being held for and hope that a simple swap accounted for the mistake. So I do that, and lo and behold, I find the book and my patron is elated. Only one small hitch, though. The book it had been mixed up with was not the right book for the other patron, which meant that something potentially far more serious (and far more difficult to fix) had gone wrong: it was possible that a whole crop of holds - who knew how many? - were all off by one. I followed the trail of swapped books with a mixture of fascination and dread, wondering just how compounded the error was. In the end, the damage wasn't all that bad - four books. But in my mind, I could see the entire Hold Shelf unravelling, swapped hold by swapped hold, like one of those gargantuan domino sculptures you used to see all the time, until nothing but the empty stacks themselves remained.