It's the night before Hogswatch. And it's too quiet.
Where is the big jolly fat man? There are those who believe and those who don't, but either way it's not right to find Death creeping down chimneys and trying to say Ho Ho Ho. Superstition makes things work in Discworld, and undermining it can have Consequences, particularly on the last night of the year when the time is turning. Susan the gothic governess has got to sort everything out by morning, otherwise there won't be a morning. Ever again...