Maskerade (Discworld Novels, Band 18)

'I thought: opera, how hard can it be? Songs. Pretty girls dancing. Nice scenery. Lots of people handing over cash. Got to be better than the cut-throat world of yoghurt, I thought. Now everwhere I go there's...'

Death, to be precise. And plenty of it. In unpleasant variations. This isn't real life - it's worse. This is the Opera House, Ankh-Morpork...a huge, rambling building, where innocent young sopranos are lured to their destiny by a strangely-familiar evil mastermind in a mask and evening dress, with a penchant for lurking in shadows, occasional murder, and sending little notes full of maniacal laughter and exclamation marks. Opera can do that to a man.

But Granny Weatherwax, Discworld's most famous witch, is in the audience. And she doesn't hold with that sort of thing. So there's going to be trouble (but nevertheless a good evenin's entertainment with murders you can really hum...). And the show MUST go on.