Maskerade — Terry Pratchett

IT'S NOT OVER TILL THE FAT LADY SINGS

There's a Ghost in the Opera House of Ankh-Morpork. It wears a bone-white mask and terrorizes the entire company, including the immortal Enrico Basilica, who eats continuously even when he's singing. Mostly spaghetti with tomato sauce.

What better way to flush out a ghost than with a witch? Enter the Opera's newest diva, Perdita X. Nitt, a wannabe witch with such an astonishing range that she can sing harmony with herself. And does.

To further complicate matters (and why not?) there is a backstage cat who occasionally becomes a person just because it's so easy. Not to mention Granny Weatherwax's old friend, Death, whose scythe arm is sore from too much use. And who has been known to don a mask .. .