So, definitions seem a good place to start. Or at least definitions as I understand them (not trying to teach anyone to suck eggs here!) In the context of a novel/film/story of any kind, a ticking clock is a writerly device that's essential to the success of the story. It's connected to, and enhances, the stakes of the story (what is at stake if the hero doesn't succeed), and provides an element of tension in the overall story arc (if the hero doesn't succeed by a certain point, X awful thing will happen). I say it's essential (and I realise there are exceptions to every rule) because without a ticking clock, a story might drift along pleasantly enough, but it lacks the element of compulsion that keeps a reader turning pages.
There are lots of kinds of ticking clock, and degrees of subtlety to which they can be employed. Some involve a literal clock — can the hero figure out how to divert the tidal wave in the 12 hours before it hits New York; Will the hero win the girl before she emigrates to Australia at the end of the month? Others are subtle and implied — will the heroine learn what caused her mother's breakdown before history repeats and she falls prey herself? Can the chocolatier win over the villagers with her confectionery before the straight-laced curate turns them all against her? Sometimes, the clock ticks away subtley over a very long time — will Pip grow up into a well-rounded young man before Miss Havisham's malign influence corrupts him?
Whether big and dramatic, or more subtle, the ticking clock serves the same purpose of setting a deadline for the main story arc, and ratcheting up the tension and urgency in the story. Often, something unexpected happens along the way to shorten the deadline further and pile on more pressure.
Now, that's all very well and good. I understand the device and recognise it in films and novels alike, but I've always been really bad at employing it to full advantage myself. I kind of forget about it. Or at least, I neglect to employ it effectively enough, which means my stories tend to just ... drift.
When I realised I was falling into the same trap with MoulderingBook, it was an important moment for me, because the story arc needs a very specific ticking clock in order to have maximum impact. The clock was already kind of present in the culmination of the story, but what I needed to do was pinpoint it and signpost it much more clearly throughout.
The specific trigger for my realisation was two-fold. Firstly, I've been re-reading Maggie Stiefvater's excellent "Shiver" trilogy, each book of which has a ticking clock that is different from the others, but which builds on those in its predecessor books. Secondly, I had a conversation with a friend about a compluter game she enjoys playing in which her character has to solve a mystery, but also — and this is what caught my interest — she has been wrongly accused of a crime to which that mystery relates, and the cops are on her trail. Can she solve the mystery and prove her innocence before the cops catch up with her? A nice ticking clock, which adds an urgency to the quest.
So, what I'm doing with MoulderingBook is seeding the ground of the first third of the story with initial 'ticks' of the clock. Then, having set my scene, I'm going to specify what my ticking clock is — X will happen if my heroine doesn't find a way to do Y before the villagers realise what's going on.
So there you have it, windancer, for what it's worth. I hope my ramblings have been interesting/useful/at least spelled correctly. And thanks for getting my brain working; it's been fun.