Going Postal

win.”
    “Hah!” said Moist.
    “We’ll come up with some other way in a week or two,” said Undecided Adrian. “Can’t you put it off until then?”
    “No, I don’t think so.”
    “Sorry,” said Undecided Adrian. He was playing idly with a small glass tube, full of red light. When he turned it over, it filled with yellow light.
    “What’s that?” Moist asked.
    “A prototype,” said Undecided Adrian. “It could have made the Trunk almost three times faster at night. It uses perpendicular molecules. But the Trunk’s just not open to new ideas.”
    “Probably because they explode when dropped?” said Sane Alex.
    “Not always .”
    “I think I could do with some fresh air,” said Moist.
    They stepped out into the night. In the middle distance, the terminal tower still winked, and one or two towers were alight in other parts of the city.
    “What’s that one?” he said, like a man pointing to a constellation.
    “Thieves’ Guild,” said Undecided Adrian. “General signals for the members. I can’t read ’em.”
    “And that one? Isn’t that the first tower on the way to Sto Lat?”
    “No, it’s the Watch station on the Hubwards Gate. General signals to Pseudopolis Yard.”
    “It looks a long way off.”
    “They use small shutter boxes, that’s all. You can’t see Tower 2 from here, the university’s in the way.”
    Moist stared, hypnotized, at the lights.
    “I wondered why that old stone tower on the way to Sto Lat wasn’t used when the Trunk was built? It’s in the right place.”
    “The old wizard tower? Robert Dearheart used it for his first experiments, but it’s a bit too far, and the walls aren’t safe, and if you stay in there for more than a day at a time, you go mad. It’s all the old spells that got into the stones.”
    There was silence, and then they heard Moist say, in a slightly strangled voice: “If you could get onto the Grand Trunk tomorrow, is there anything you could do to slow it down?”
    “Yes, but we can’t,” said Undecided Adrian.
    “Yes, but if you could?”
    “Well, there’s something we’ve been thinking about…” said Mad Al. “It’s very crude.”
    “Will it knock out a tower?” said Moist.
    “Should we be telling him about this?” said Sane Alex.
    “Have you ever met anyone else that Killer had a good word for?” said Undecided Adrian. “In theory, it could knock out every tower, Mr. Moist.”
    “Are you insane as well as mad?” said Sane Alex. “He’s government !”
    “Every tower on the Trunk?” said Moist.
    “Yep. In one go,” said Mad Al. “It’s pretty crude.”
    “ Really every tower?” said Moist again.
    “Maybe not every tower, if they catch on,” Mad Al admitted, as if less than wholesale destruction was something to be mildly ashamed of. “But plenty. Even if they cheat and carry it to the next tower on horseback. We call it… the Woodpecker .”
    “The woodpecker?”
    “No, not like that. You need, sort of, more of a pause for effect, like… the Woodpecker .”
    “ …The Woodpecker ,” said Moist, more slowly.
    “You’ve got it. But we can’t get it onto the Trunk. They’re on to us.”
    “Supposing I could get it onto the Trunk?” said Moist, staring at the lights. The towers themselves were quite invisible now.
    “You? What do you know about clacks codes?” said Undecided Adrian.
    “I treasure my ignorance,” said Moist. “But I know about people. You think about being cunning with codes. I just think about what people see…”
    They listened. They argued. They resorted to mathematics, while words sailed through the night above them.
    And Sane Alex said: “All right, all right. Technically it could work, but the Trunk people would have to be stupid to let it happen.”
    “But they’ll be thinking about codes,” said Moist. “And I’m good at making people stupid. It’s my job.”
    “I thought your job was postmaster,” said Undecided Adrian.
    “Oh, yes. Then it’s my vocation.”
    The Smoking Gnu looked at one another.
    “It’s a totally mad idea,” said Mad Al, grinning.
    “I’m glad you like it,” said Moist.

    T HERE ARE TIMES when you just have to miss a night’s sleep. But Ankh-Morpork never slept; the city never did more than doze, and would wake up around three A.M. for a glass of water.
    You could buy anything in the middle of the night. Timber? No problem. Moist wondered whether there were vampire carpenters, quietly making vampire chairs. Canvas? There