Guards! Guards!

some of them might have remembered the subsequent events and formed a pretty good and gut-churning insight, to whit, that one of the things sometimes forgotten about the human spirit is that while it is, in the right conditions, noble and brave and wonderful, it is also, when you get right down to it, only human.
    The dragon flame caught him full on the chest. For a moment he was visible as a white-hot outline before the neat, black remains spiraled down into a little puddle of melting cobbles.
    The flame vanished.
    The crowd stood like statues, not knowing if it was staying put or running that would attract more attention.
    The dragon stared down, curious to see what they were going to do next.
    Colon felt that, as the only civic official present, it was up to him to take charge of the situation. He coughed.
    “Right, then,” he said, trying to keep the squeak out of his voice. “If you would just move along there, ladies and gentlemen. Move along, now. Move along. Let’s be having you, please.”
    He waved his arms in a vague gesture of authority as the people shuffled nervously away. Out of the corner of his eye he saw red flames behind the rooftops, and sparks spiraling in the sky.
    “Haven’t you got any homes to go to?” he croaked.

    The Librarian knuckled out into the Library of the here and now. Every hair on his body bristled with rage.
    He pushed open the door and swung out into the stricken city.
    Someone out there was about to find that their worst nightmare was a maddened Librarian.
    With a badge.

    The dragon swooped leisurely back and forth over the nighttime city, barely flapping its wings. It didn’t need to. The thermals were giving it the lift it needed.
    There were fires all over Ankh-Morpork. So many bucket chains had formed between the river and various burning buildings that buckets were getting misdirected and hijacked. Not that you really needed a bucket to pick up the turbid waters of the river Ankh—a net was good enough.
    Downstream, teams of smoke-stained people worked feverishly to close the huge, corroded gates under the Brass Bridge. They were Ankh-Morpork’s last defense against fire, since then the Ankh had no outlet and gradually, oozingly, filled the space between the walls. A man could suffocate under it.
    The workers on the bridge were the ones who couldn’t or wouldn’t run. Many others were teeming through the gates of the city and heading out across the chilly, mist-wreathed plains.
    But not for long. The dragon, looping and curving gracefully above the devastation, glided out over the walls. After a few seconds the guards saw actinic fire stab down through the mists. The tide of humanity flowed back, with the dragon hovering over it like a sheepdog. The fires of the stricken city glowed redly off the underside of its wings.
    “Got any suggestions about what we do next, Sergeant?” said Nobby.
    Colon didn’t reply. I wish Captain Vimes were here, he thought. He wouldn’t have known what to do either, but he’s got a much better vocabulary to be baffled in.
    Some of the fires went out as the rising waters and the confused tangle of fire chains did their work. The dragon didn’t appear to be inclined to start anymore. It had made its point.
    “I wonder who it’ll be,” said Nobby.
    “What?” said Carrot.
    “The sacrifice, I mean.”
    “Sergeant said people wouldn’t put up with it,” said Carrot stoically.
    “Yeah, well. Look at it this way: if you say to people, what’s it to be, either your house burned down around you or some girl you’ve probably never met being eaten, well, they might get a bit thoughtful. Human nature, see.”
    “I’m sure a hero will turn up in time,” said Carrot. “With some new sort of weapon, or something. And strike at its voonerable spot.”
    There was the silence of sudden intense listening.
    “What’s one of them?” said Nobby.
    “A spot. Where it’s voonerable. My grandad used to tell me stories. Hit a dragon in its voonerables, he said, and you’ve killed it.”
    “Like kicking it in the wossnames?” said Nobby, interestedly.
    “Dunno. I suppose so. Although, Nobby, I’ve told you before it is not right to—”
    “And where’s the spot, like?”
    “Oh, a different place on each dragon. You wait till it flies over and then you say, there’s the voonerable spot, and then you kill it,” said Carrot. “Something like that.”
    Sergeant Colon stared blankly into space.
    “Hmm,” said Nobby.
    They