In the Necessary and Unnecessary Sounds Control Department, Ms Rozalia Szum had a gig every day. At seven fifteen she calibrated the echoes in the corridor, at seven thirty she stamped the legal 'tap-tap' of doorknobs. Petitioners brought cases: a whisk that whistled out of tune, a pigeon that applauded at inappropriate times. Rozalia loved the order of the noise, that daily orchestra of predictable sighs, scrapes and bells that kept the Whistlehouse in check. That morning she had prepared the 'Great Murmur Review', an annual audit of everything that sounded before it sounded bad. The mayor expected a certificate of audibility from the city, and councillors threatened to revise the silence budget. Rozalia had a plan: from the 'ding' of the tram to the 'ah' in the queue for the yeasties, every sound would get a stamp. And if something squeaks without authority, it will also get a reprimand, a protocol and a voucher for grease. At the first checkpoint, she heard something that had no right to be on the roster. It sounded like the tempering of a pencil inside a lift, yet no lift trembled. Her decibel meter, a device more pertinent than an old lady with a balcony, showed the message: "That's not a sound. It's a comment." Rozalia furrowed her eyebrows, grabbed her service torch and followed the whisper that fled down the corridor towards the archives. At the gatehouse, Mr Felix, the self-appointed custodian of the keys, lifted the paper and, without looking, pronounced that it was probably the Queue Whisperer. He usually buzzes at the window when the numbers run out and the tension builds. Sound was the first to react: he wrote one word on the "Do not touch" sign in chalk: "Still". And then the printer, which was out of paper, printed her a note out of nowhere: "Rozalia, don't write me down". The phone blared its service tune, and the duty officer reported over the loudspeaker: we have a four hundred and four - an uncatalogued sound in the sewer pipes, risk level: collective screeching. Rozalia picked up her torch, Mr Felix and the protocol, then went down to the basement, where the pipe streams had their own labels and humours. On each knee stood a warning that dripping continuously was a misdemeanour, and each 'plum' had a liability attached to it. The whisper spoke again, this time arranging the drops on the floor into the word 'Here', as if writing in a wet alphabet. In front of them was a service hatch with a sign reading 'Pipe Behaviour - for the curious with powers only', which in official language meant trouble. Rozalia unscrewed three screws, the fourth jumped to the floor and rolled, clanking like an amused token. Then all the sounds of the city suddenly quietened, as if holding their breath. Something clattered hard from underneath, exactly to the rhythm of her loudly beating heart. The decibel meter, hitherto bored, suddenly popped up in green and yellow stripes and wailed loudly in warning. And a sound that refused to be written down trembled in letters on her notepad: "Don't look ... unless you like surprises." Rozalia smiled briefly, counted to three and lifted the flap carefully upwards.