The Fifth Elephant - Terry Pratchett

The Discworld is very much like our own - if our own were to consist of a flat planet balanced on the back of four elephants which stand on the back of a giant turtle, that is . . .Well, he thought, so this is diplomacy. It's lying, only for a better class of people. They say that diplomacy is a gentle art.That mastering it is a lifetime's work. But you do need a certain inclination in that direction. It's not something you can just pick up on the job.A few days ago Sam Vimes was a copper - an important copper, true - chief of police - but still, at his core, a policeman. But today he is an ambassador - to the mysterious, fat-rich country of Uberwald. Today, Sam Vimes is also a man on the run.At some point during his ambassadorship, things went very wrong. It's snowing. It's freezing.And if Vimes can't make it through the forest, with only his wits and the gloomy trousers of Uncle Vanya (don't ask), there's going to be a terrible war. There are monsters on his trail. They're bright.They're fast. They're werewolves - and they're catching up.