Maskerade

Vimes had been promoted to Commander he seemed to be enrolling people who asked questions all the time. It was even affecting Detritus, considered by other trolls to be as dim as a dead glowworm.
    Detritus reached down and picked up an eye patch.
    “What d’you think, then?” said Nobby scornfully. “You think he turned into a bat and flew away?”
    “Ha! I do not t’ink that ’cos it is in…consist…ent with modern policing,” said Detritus.
    “Well, I think,” said Nobby, “that when you have ruled out the impossible, what is left, however improbable, ain’t worth hanging around on a cold night wonderin’ about when you could be getting on the outside of a big drink. Come on. I want to try a leg of the elephant that bit me.”
    “Was dat irony?”
    “That was metaphor.”
    Detritus, uneasy in what was technically his mind, prodded at the torn pieces of clothing.
    Something brushed against his leg. It was a cat. It had tattered ears, one good eye, and a face like a fist with fur on it.
    “Hello, little cat,” said Detritus.
    The cat stretched and grinned. “Gerrt lorssst, coppuurrrr…”
    Detritus blinked. There are no such things as troll cats, and Detritus had never seen a cat before he’d arrived in Ankh-Morpork and discovered that they were very, very hard to eat. And he’d never heard of them talking. On the other hand, he was very much aware of his reputation as the most stupid person in the city, and he wasn’t going to draw attention to a talking cat if it were going to turn out that everybody except him knew that they talked all the time.
    In the gutter, a few feet away, there was something white. He picked it up carefully. It looked like the mask the Ghost had worn.
    This was probably a Clue.
    He waved it urgently. “Hey, Nobby—”
    “Thank you.” Something dipped through the darkness, snatched the mask from the troll’s hand, and soared into the night.
    Corporal Nobbs turned around. “Yes?” he said.
    “Er…how big are birds? Normally?”
    “Oh, blimey, I dunno. Some are small, some are big. Who cares?”
    Detritus sucked his finger. “Oh, no reason,” he said. “I am far too smart to be taken in by perfec’ly normal t’ings.”

    Something squelched underfoot.
    “It’s pretty damp down here, Walter,” said Nanny.
    And the air was stale and heavy and seemed to be squeezing the light from the torch. There was a dark edge to the flame.
    “Not far now Mrs. Ogg!”
    Keys jingled in the darkness, and some hinges creaked.
    “I found this Mrs. Ogg! It’s the Ghost’s secret cave!”
    “Secret cave, eh?”
    “You got to shut your eyes! You got to shut your eyes!” said Walter urgently.
    Nanny did so, but to her shame kept a grip on the torch, just in case. She said: “And is the Ghost in there, Walter?”
    “No!”
    There was the rattle of a matchbox and some scuffling, and then—
    “You can open them now Mrs. Ogg!”
    Nanny did so.
    Color and light blurred and then swam into focus, first in her eyes and then, eventually, in her brain. “Oh, my,” she murmured. “Oh, my, my…”
    There were candles, the big flat ones used to illuminate the stage, floating in shallow bowls. The light they gave was soft, and it rippled over the room like the soul of water.
    It glinted off the beak of a huge swan. It glittered in the eye of a vast, sagging dragon.
    Nanny Ogg turned slowly. Her experience of opera had not been a lengthy one but witches pick things up quickly, and there was the winged helmet worn by Hildabrun in The Ring of the Nibelungingung , and here was the striped pole from The Barber of Pseudopolis , and there was the pantomime horse with the humorous trapdoor from The Enchanted Piccolo , and here…
    …here was opera, all piled in a heap. Once the eye had taken it all in, it had time to notice the peeling paint and rotting plaster and the general air of gentle moldering. The decrepit props and threadbare costumes had been dumped in here because people didn’t want them anywhere else.
    But someone did want them here. After the eye had seen the ruin, then there was time for it to see the little patches of recent repair, the careful areas of fresh paint.
    There was something like a desk in the tiny area of floor not occupied by the props. And then Nanny realized that it had a keyboard and a stool, and there were neat piles of paper on top of it.
    Walter was watching her with a big, proud grin.
    Nanny ambled over to the thing. “It’s a harmonium,