A/N:... Well, it has been a long time since I last wrote Disc fic. Please read and review!

Somewhere in the depths of the mountains, near the History Monks but not too near, is a small temple festooned in multicoloured prayer flags. If you enter this temple, carefully avoiding the dead mice, destroy the magical wards about the altar, persuade a Hero to move the altar, cut through the rusted padlock on the trap door beneath, get the Hero to open the trapdoor and allow him or her to go down the ladder first, wait for the screams to end and then go down yourself with a supply of liquorice bootlaces to placate the spirits... then you come to a cavern. A cavern high and wide, stretching as far as the eye can see and possibly a bit further. Damp and musty, it contains thousands of bottles, hovering in the air, filled with strange and arcane substances that glitter like Cheery’s special-occasions axe-bag and glow with a soft, deadly light which you can’t see because it’s octarine.

These bottles sink or rise, according to how heavy they are. Some are larger than others. Every now and then, one falls and smashes on the floor, and a burst of octarine light floods the cave for a moment, and then dies away, leaving a smell of burnt toast behind.

This is the Cavern of Belief. It is responsible for several hundred deaths, thousands of medical myths, and a number of household accidents, as well as the existence of Mr. Lipwig, Esq., and the fact that there has never been a truly successful invasion of Ankh-Morpork- because people believe that Ankh-Morpork can’t be invaded in the same way that they believe that Mr. Lipwig means well, because he’s the man with the golden suit.

Some time previously, a man named Samuel Vimes had obstructed the traffic for just a little too long in the amusingly named Bonk, Uberwald, causing the driver to lose half an ear to frost-bite and ruining his dreams of becoming a world-famous ventriloquist.

Every night since then, the hapless would-be ventriloquist, after tenderly salving his remaining half-ear as Igor had told him to and saying his prayers, had cursed Sir Samuel Vimes and Ankh-Morpork to the deepest pits of fiery hell for being the wretched cause of his asymmetry. The first curses had created a very small bottle in the Cavern of Belief, which had grown heavier... and heavier... until one night, the curses reached a critical point and the bottle tumbled to the floor and smashed.

There was a very small flash of octarine light, and the Cavern of Belief got on with believing.

In the meantime, Sam Vimes was on the beat. There was no particular reason for this, apart from the fact that he had always been keen on people knowing the streets and felt he should patrol every now and then to set a good example. Or, to be more exact, he just wanted to.

Angua had come with him; he had not asked her to, but he had seen the tiniest flicker of Carrot’s and Angua’s eyes towards each other as he stumped out of the door in full uniform plus helmet, and then Angua had risen from her seat, seized truncheon and helmet, and caught up with him quickly, eyes dead ahead and innocent, already settling into the usual nice steady pace. He’d shot her a look, muttered a bit, and lit a cigar, but Angua knew him well and she didn’t bother to talk to him, just walked out across New Bridge, along Holofernes Street and down Peach Pie Street, where it happened.

In the Cavern of Belief the bottle smashed-

-and in Ankh-Morpork, a brick fell out of the sky and hit Sam Vimes on the head.

For a fraction of a moment, Angua just stared, mouth open, at the sight of Vimes on the floor, apparently out cold, and the brick next to him, apparently perfectly normal, and then in the manner of suspicious coppers everywhere, looked up. She couldn’t see anyone there- she sniffed –and she couldn’t smell anyone there either. Angua stood there, a puzzled frown between her eyebrows, and then spun round suddenly. “Oh no you don’t, Otto! The commander being hit by a falling brick is not news. Take a picture of the house and get de Worde to write about the... the decay of the capital’s buildings or something. And bugger off, you miserable lot,” she added to the crowd already congealing around the scene. Commander Vimes was already stirring; she could hear the mumbled swearwords as he surfaced.

He got up from the pavement, staggering a bit, and Angua grasped his arm before he fell. “Wha’?...”

“You were hit by a falling brick, Commander,” Angua said soothingly, trying not to laugh as the funny side became obvious. Vimes’s eyes were narrowed; he was glaring around, looking for his attacker.

“Mmrgh,” Commander Vimes said. His helmet was askew on his head, unbalanced by the rapidly swelling lump.

Angua couldn’t help it. A giggle squeezed out, and another, and another when Vimes gave her the evil eye, on which she handed it back and was forced to support herself against the wall, still laughing.

“Sergeant!” Vimes snapped. “Consider your next month’s armour allowance docked!”

Angua controlled herself. “Yessir. Sorry, sir.”

Vimes eyed her suspiciously, but allowed himself to be towed back to Pseudopolis Yard, where Angua gave him into Igor’s care with the strict injunction that his brain was not to be switched, improved, tweaked or otherwise tinkered with and went off to find Sally and Cheery. Carrot was less aggravating company, but he couldn’t gossip worth a damn.

“... So this brick falls pretty much out of the sky and hits Mister Vimes... and I” snort- “I-” snicker- “just- couldn’t- stop- laughing!”

Much laughter.

“He docked my armour allowance for it, though. Damned brick.”

“Oh, bad luck... Another Neck Bolt? Next round’s on me.”

Ponder Stibbons, passing by a particular area of HEX that seemed to measure belief concentration in the city (no-one knew how, or why, and they hadn’t actually worked out that that was what it was doing until the readings from That Hogswatch were so extraordinary and they put their minds to solving the problem), stopped dead still and carefully picked up a piece of thin HEX paper HEX had spewed out. There was a sudden spike in it, at about half-past twelve that day.

“Hm,” Ponder said, putting it down again. “Interesting.”

And then he completely forgot about it.