Today's thought: when is a law of writing not a law?
Anton Chekhov (paraphrased): if you put a gun on the mantlepiece in Act 1, it must be fired no later than the end of Act 3. (Of a three act play).
This is pretty much a rule to live by, at least when you're starting out writing fiction: if there are lots of dangling loose threads in your story, diverticulae that don't go anywhere, then you're wasting words and misleading your readers.
However. It's not a rule to be taken as an absolute requirement.
Consider the crime novel. Your classic murder-mystery-whodunnit is almost by definition a maze of dangling threads, for the detective's overt task is to navigate among them and determine which of them are actually connected to the crime.
But not every gun has to be fired to serve a purpose within a story. Sometimes just the fact that there is a gun on the mantlepiece conveys a message. And not all guns are guns: sometimes a gun is just a signifier. There's an example in my latest novel to see print, GLASSHOUSE — click below to see the gory spoiler.
There's a gun on the mantlepiece in GLASSHOUSE -- or rather, a crossbow. Reeve makes it while she's planning a break-out, in the early days of her incarceration. But the crossbow is never used to shoot anyone. On that basis some readers accused me of breaking Chekhov's dictum -- it looks to them like a dangling thread. But the crossbow does serve a narrative purpose; it's just not the one they expect. Making the device catalyses Reeve's nervous breakdown. It's a grotesquely inappropriate tool given her goal of escaping from the Glasshouse, which is an existential (rather than a physical) prison. Howver, it's in keeping with her initial outlook, that of the secret agent infiltrating an enemy camp; she doesn't understand the nature of her detention. Thus, it serves to expose her cognitive dissonance to herself (hence in large measure her breakdown when she realizes that it's not going to work).