With a silence that was frightening, the clacks tower across the street lit up. The big squares glowed into life one after the other. For a moment, Moist saw the shape of the lamplighter in front of one of the shutters.
As he disappeared into the dark, the tower started to flicker. It was close enough to illuminate the roof of the Post Office.
There were three dark figures at the other end of the roof, watching Moist. Their shadows danced as the pattern of lights changed, twice every second. They revealed the figures were human, or at least humanoid. And they were walking towards him.
Gods, now, gods could be humanoid. And they didn't like to be messed about.
Moist cleared his throat. ‘I'm certainly glad to see you—' he croaked.
‘Are you Moist?' said one of the figures.
‘Look, I—'
‘She said you'd be kneeling down,' said another member of the celestial trio. ‘Fancy a cup of tea?'
Moist got up slowly. This was not godly behaviour.
‘Who are you?' he said. Emboldened by the lack of thunderbolts, he added: ‘And what are you doing on my building?'
‘We pay rent,' said a figure. ‘To Mr Groat.'
‘He never told me about you!'
‘Can't help you there,' said the shadow in the centre. ‘Anyway, we've only come back to get the rest of our stuff. Sorry about your fire. It wasn't us.'
‘You being—' said Moist.
‘I'm Mad Al, he's Sane Alex, and that's Adrian, who says he's not mad but can't prove it.'
‘Why do you rent the roof?'
The trio looked at one another.
‘Pigeons?' suggested Adrian.
‘That's right, we're pigeon fanciers,' said the shadowy figure of Sane Alex.
‘But it's dark,' said Moist. This information was considered.
‘Bats,' said Mad Al. ‘We're trying to breed homing bats.'
‘I don't believe bats have that kind of homing instinct,' said Moist.
‘Yes, it's tragic, isn't it?' said Alex.
‘I come up here at nights and see those empty little perches and it's all I can do not to cry,' said Undecided Adrian.
Moist looked up at the little tower. It was about five times the height of a man, with the control levers on a polished panel near the bottom. It looked... professional, and well used. And portable.
‘I don't think you breed any kind of birds up here,' he said.
‘Bats are mammals,' said Sane Alex. Moist shook his head.
‘Lurking on rooftops, your own clacks... you're the Smoking Gnu, aren't you?'
‘Ah, with a mind like that I can see why you're Mr Groat's boss,' said Sane Alex. ‘How about a cup of tea?'
Mad Al picked a pigeon feather out of his mug. The pigeon loft was full of the flat, choking smell of old guano.
‘You have to like birds to like it up here,' he said, flicking the feather into Sane Alex's beard.
‘Good job you do, eh?' said Moist.
‘I didn't say I did, did I? And we don't live up here. It's just that you've got a good rooftop.'
It was cramped in the pigeon loft, from which pigeons had, in fact, been barred. But there's always one pigeon that can bite through wire netting. It watched them from the corner with mad little eyes, its genes remembering the time it had been a giant reptile that could have taken these sons of monkeys to the cleaners in one mouthful. Bits of dismantled mechanisms were everywhere.
‘Miss Dearheart told you about me, did she?' said Moist.
‘She said you weren't a complete arse,' said Undecided Adrian.
‘Which is praise coming from her,' said Sane Alex.
‘And she said you were so crooked you could walk through a corkscrew sideways,' said Undecided Adrian. ‘She was smiling when she said it, though.'
‘That's not necessarily a good thing,' said Moist. ‘How do you know her?'
‘We used to work with her brother,' said Mad Al. ‘On the Mark 2 tower.'
Moist listened. It was a whole new world.
Sane Alex and Mad Al were old men in the clacks business; they'd been in it for almost four years. Then the consortium had taken over, and they'd been fired from the Grand Trunk on the same day that Undecided Adrian had been fired from the Alchemists' Guild chimney, in their case because they'd spoken their mind about the new management and in his case because he hadn't moved fast enough when the beaker started to bubble.
They'd all ended up working on the Second Trunk. They'd even put money into it. So had others. It had all kinds of improvements, it would be cheaper to run, it was the bee's knees, mutt's nuts and various wonderful bits of half a dozen other creatures. And then John Dearheart, who always used a safety lanyard, landed in the cabbage field and that was the end of the Second Trunk.
Since then, the trio had done the kinds of jobs available to new square pegs in a world of old round holes, but every night, high above, the clacks flashed its messages. It was so close, so inviting, so... accessible. Everyone knew, in some vague, half-understood way, that the Grand Trunk had been stolen in all but name. It belonged to the enemy.
So they'd started an informal little company of their own, which used the Grand Trunk without the Grand Trunk's knowing.
It was a little like stealing. It was exactly like stealing. It was, in fact, stealing. But there was no law against it because no one knew the crime existed, so is it really stealing if what's stolen isn't missed? And is it stealing if you're stealing from thieves? Anyway, all property is theft, except mine.
‘So now you're, what was it again... crackers?' Moist said.
‘That's right,' said Mad Al. ‘Because we can crack the system.'
‘That sounds a bit over-dramatic when you're just doing it with lamps, doesn't it?'
‘Yes, but "flashers" was already taken,' said Sane Alex.
‘All right, but why "Smoking Gnu"?' said Moist.
‘That's cracker slang for a very fast message sent throughout the system,' said Sane Alex proudly.
Moist pondered this. ‘That makes sense,' he said. ‘If I was a team of three people, who all had a first name beginning with the same letter, that's just the kind of name I'd choose.'
They'd found a way into the semaphore system, and it was this: at night, all clacks towers were invisible. Only the lights showed. Unless you had a good sense of direction, the only way you could identify who the message was coming from was by its code. Engineers knew lots of codes. Ooh, lots.
‘You can send messages free?' said Moist. ‘And nobody notices?'
There were three smug smiles. ‘It's easy,' said Mad Al, ‘when you know how.'
‘How did you know that tower was going to break down?'
‘We broke it,' said Sane Alex. ‘Broke the differential drum. They take hours to sort out because the operators have to—'
Moist missed the rest of the sentence. Innocent words swirled in it like debris caught in a flood, occasionally bobbing to the surface and waving desperately before being pulled under again. He caught ‘the' several times before it drowned, and even ‘disconnect' and ‘gear chain', but the roaring, technical polysyllables rose and engulfed them all.
‘—and that takes at least half a day,' Sane Alex finished.
Moist looked helplessly at the other two. ‘And that means what, exactly?' he said.
‘If you send the right kind of message you can bust the machinery,' said Mad Al.
‘The whole Trunk?'
‘In theory,' said Mad Al, ‘because an execute and terminate code—'
Moist relaxed as the tide came back in. He wasn't interested in machinery; he thought of a spanner as something which had another person holding it. It was best just to smile and wait. That was the thing about artificers: they loved explaining. You just had to wait until they reached your level of understanding, even if it meant that they had to lie down.
‘—can't do that any more in any case, because we've heard they're changing the—'
Moist stared at the pigeon for a while, until silence came back. Ah. Mad Al had finished, and by the looks of things it hadn't been on a high note.
‘You can't do it, then,' said Moist, his heart sinking.
‘Not now. Old Mr Pony might be a bit of an old woman but he sits and niggles at problems. He's been changing all the codes all day! We've heard from one of our mates that every signaller will have to have a personal code now. They're being very careful. I know Miss Adora Belle thought we could help you, but that bastard Gilt has locked things up tight. He's worried you're going to 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 towers were alight here and there 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.'