Hogfather

'OH, THERE HAS TO BE SOMETHING IN THE STOCKING THAT MAKES A NOISE, said Death, OTHERWISE WHAT IS 4:30 A.M. FOR?'

Superstition makes things work in the Discworld and undermining it can have Consequences. It's just not right to find Death creeping down chimneys and trying to say Ho Ho Ho . . .

It's the last night of the year, the time is turning, and if Susan, Gothic governess and Death's granddaughter (sort of), doesn't sort everything out by morning, there won't be a morning. Ever again . . .

'Has the energy of The Hitchhiker's Guide to the Galaxy and the inventiveness of Alice in Wonderland' Sunday Times

Hogfather is the fourth book in the Death series, but you can read the Discworld novels in any order.