There was an old, very old Borogravian song with more more Zs and Vs in it than any lowlander can pronounce. It was called 'Plogviehze!' It meant 'The Sun Has Risen! Let's Make War!' You needed a special kind of history to get all that into one word.
   Sam Vimes sighed. The little countries here fought because of the river, because of idiot treaties, because of royal rows, but mostly they fought because they always fought. They made war, in fact, because the sun came up.
   This war had tied itself into a knot.

Monstrous Regiment heralds the author's return to young female protagonists (well, if you don't count Susan). It's set in Borogravia, a country famous for fighting everyone over nothing, all the time. They have an insane god which has abominated everything from beetroot to jigsaw puzzles to the colour blue (devout people try not to look at the sky.)

   There was a bird whistle as Polly neared the hiding place. She identified this one as the sound of the Very Bad Bird Impersonator, and made a note to teach ... some bird calls that at least sounded real. They were harder to do than most people thought.

Polly is the central character, something of the author's alter ego, if his alter egos are usually young and blond and extremely smart... Polly is all of these things. In a country where it doesn't pay to ask questions, especially questions like "why are we fighting?", Polly has been given a brain. Not a useful thing for a barmaid to have, but then, her elder brother Paul has gone without one his whole life, and look where it got him. Er - that is, Polly doesn't know where dear, dim, bird-watching Paul has gone, and has decided to go find out. Since girls cannot inherit "the things of men" (ie everything of value) under Nugganatic law, she decides to go find Paul, who might be able to inherit the family's large inn, but would never be able to run it. He can't even add figures, while Polly's been illegally reading, writing and adding up for years.

   Birds sang. The effect was peaceful, if you didn't know about birdsong, but Polly could recognise the alarm calls close by and the territorial threats far off and, everywhere, the preoccupation with sex. That took the edge off the pleasure.*

[*It's hard to be an ornithologist and walk through a wood when all around you the world is shouting: 'Bugger off, this is my bush! Aargh, the nest thief! Have sex with me, I can make my chest big and red!']

Paul joined the army, and went off to fight in yet another of Borogravia's pointless wars. He hasn't been heard from in a long time, and if he's dead, the inn will eventually go to Polly's cousin the drunkard. So, she dresses up as a boy, kisses the Duchess (ie joins the army) and marches off to the front, accompanied by a troll, a vampire, a sergeant who's rounder than an indiarubber ball, a screaming loony of a corporal, and a bunch of other fourteen-year-olds. No-one told them they're the last recruits, that their country is losing the war, and the aforepromised steak and bacon is not, actually, on the mess menu. They should have guessed, though, from all the refugees wondering past carrying anything edible on their backs, and the wounded soldiers coming home, minus some limbs but with rather unattractive pot-metal medals rusting on their breasts as compensation.

   There have been better attempts at marching, and they have been made by penguins. Sergeant Jackrum brought up the rear in the cart, shouting instructions, but the recruits moved as if they'd never before had to get from place to place. The sergeant yelled the swagger out of their steps, stopped the cart and for a few of them held an impromptu lesson in the concepts of 'right' and 'left' and, by degrees, they left the mountains.