Guards! Guards!

we found we’ve got a lot in common. It’s an amazing coincidence, but my grandfather once had his grandfather whipped for malicious lingering.”
    That must make them practically family, Vimes thought. Another stab of pain from his stricken side made him wince.
    “You’ve got some very bad bruising and probably a cracked rib or two,” she said. “If you roll over I’ll put some more of this on.” Lady Ramkin flourished a jar of yellow ointment.
    Panic crossed Vimes’s face. Instinctively, he raised the sheets up around his neck.
    “Don’t play silly buggers, man,” she said. “I shan’t see anything I haven’t seen before. One backside is pretty much like another. It’s just that the ones I see generally have tails on. Now roll over and up with the nightshirt. It belonged to my grandfather, you know.”
    There was no resisting that tone of voice. Vimes thought about demanding that Nobby be brought in as a chaperon, and then decided that would be even worse.
    The cream burned like ice.
    “What is it?”
    “All kinds of stuff. It’ll reduce the bruising and promote the growth of healthy scale.”
    “What?”
    “Sorry. Probably not scale. Don’t look so worried. I’m almost positive about that. Okay, all done.” She gave him a slap on the rump.
    “Madam, I am Captain of the Night Watch,” said Vimes, knowing it was a bloody daft thing to say even as he said it.
    “Half naked in a lady’s bed, too,” said Lady Ramkin, unmoved. “Now sit up and eat your tea. We’ve got to get you good and strong.”
    Vimes’s eyes filled with panic.
    “Why?” he said.
    Lady Ramkin reached into the pocket of her grubby jacket.
    “I made some notes last night,” she said. “About the dragon.”
    “Oh, the dragon.” Vimes relaxed a bit. Right now the dragon seemed a much safer prospect.
    “And I did a bit of working out, too. I’ll tell you this: it’s a very odd beast. It shouldn’t be able to get airborne.”
    “You’re right there.”
    “If it’s built like swamp dragons, it should weigh about twenty tons. Twenty tons! It’s impossible. It’s all down to weight and wingspan ratios, you see.”
    “I saw it drop off the tower like a swallow.”
    “I know. It should have torn its wings off and left a bloody great hole in the ground,” said Lady Ramkin firmly. “You can’t muck about with aerodynamics. You can’t just scale up from small to big and leave it at that, you see. It’s all a matter of muscle power and lifting surfaces.”
    “I knew there was something wrong,” said Vimes, brightening up. “And the flame, too. Nothing goes around with that kind of heat inside it. How do swamp dragons manage it?”
    “Oh, that’s just chemicals,” said Lady Ramkin dismissively. “They just distill something flammable from whatever they’ve eaten and ignite the flame just as it comes out of the ducts. They never actually have fire inside them, unless they get a case of blowback.”
    “What happens then?”
    “You’re scraping dragon off the scenery,” said Lady Ramkin cheerfully. “I’m afraid they’re not very well-designed creatures, dragons.”
    Vimes listened.
    They would never have survived at all except that their home swamps were isolated and short of predators. Not that a dragon made good eating, anyway—once you’d taken away the leathery skin and the enormous flight muscles, what was left must have been like biting into a badly-run chemical factory. No wonder dragons were always ill. They relied on permanent stomach trouble for supplies of fuel. Most of their brain power was taken up with controlling the complexities of their digestion, which could distill flame-producing fuels from the most unlikely ingredients. They could even rearrange their internal plumbing overnight to deal with difficult processes. They lived on a chemical knife-edge the whole time. One misplaced hiccup and they were geography.
    And when it came to choosing nesting sites, the females had all the common sense and mothering instinct of a brick.
    Vimes wondered why people had been so worried about dragons in the olden days. If there was one in a cave near you, all you had to do was wait until it self-ignited, blew itself up, or died of acute indigestion.
    “You’ve really studied them, haven’t you,” he said.
    “Someone ought to.”
    “But what about the big ones?”
    “Golly, yes. They’re a great mystery, you know,” she said, her expression becoming extremely serious.
    “Yes, you