'I believe you,' said Keith. 'It never felt a thing,' Maurice went on. There was a scream, from somewhere in a nearby street, and then the sound of crockery breaking. There had been quite a lot of that in the last half hour. 'Sounds like the lads are still at work,' said Maurice, carrying the dead mouse behind a pile of hay. 'Nothing gets a good scream like Sardines dancing across the table.' The stable doors opened. A man came in, harnessed two of the horses, and led them out. Shortly afterwards, there was the sound of a coach leaving the yard. A few seconds later, there were three loud knocks from below. They were repeated. And then they were repeated

again. Finally, Malicia's voice said: 'Are you two up there or not?' Keith crawled out of the hay and looked down. 'Yes,' he said. 'Didn't you hear the secret knock?' said Malicia, staring up at him in annoyance. 'It didn't sound like a secret knock,' said Maurice, his mouth full. 'Is that Maurice's voice?' said Malicia suspiciously. 'Yes,' said Keith. 'You'll have to excuse him, he's eating someone.' Maurice swallowed quickly. 'It's not someone!' he hissed. 'It's not someone unless it can talk! Otherwise it's just food!'

'It is a secret knock!' Malicia snapped. 'I know about these things! And you're supposed to give the secret knock in return!'

'But if it's just someone knocking on the door in, you know, general high spirits, and we knock back, what are they going to think is up here?' said Maurice. 'An extremely heavy beetle?' Malicia went uncharacteristically silent for a moment. Then she said: 'Good point, good point. I know, I'll shout “It's me, Malicia!” and then give the secret knock, and that way you'll know it's me and you can give the secret knock back. OK?'

'Why don't we just say “Hello, we're up here”? said Keith innocently. Malicia sighed. 'Don't you have any sense of drama? Look, my father's gone off to the Rathaus to see the other council members. He said the crockery was the last straw!'

'The crockery?' said Maurice. 'You told him about Sardines?'

'I had to say I'd been frightened by a huge rat and tried to climb up the dresser to escape,' said Malicia. 'You lied?'

'I just told a story,' said Malicia, calmly. 'It was a good one, too. It was much more true than the truth would sound. A tap-dancing rat? Anyway, he wasn't really interested because there's been a lot of complaints today. Your tame rats are really upsetting people. I am gloating.'

'They're not our rats, they're their rats,' said Keith. 'And they always work fast,' said Maurice proudly. 'They don't mess about when it comes to… messing about.'

'One town we were in last month, the council advertised for a rat piper the very next morning,' said Keith. 'That was Sardines' big day.'

'My father shouted a lot and sent for Blunkett and Spears, too,' said Malicia. 'They're the rat-catchers! And you know what that means, don't you?' Maurice and Keith looked at one another. 'Let's pretend we don't,' said Maurice. 'It means we can break into their shed and solve the mystery of the bootlace tails!' said Malicia. She gave Maurice a critical look. 'Of course, it would be more… satisfying if we were four children and a dog, which is the right number for an adventure, but we'll make do with what we've got.'

'Hey, we just steal from governments!' said Maurice. 'Er, only governments who aren't people's fathers, obviously,' said Keith. 'So?' said Malicia, giving Keith an odd look. 'That's not the same as being criminals!' said Maurice. 'Ah, but when we've got the evidence, we can take it to the council and then it won't be criminal at all because we will be saving the day,' said Malicia, with weary patience. 'Of course, it may be that the council and the Watch are in league with the rat-catchers, so we shouldn't trust anyone. Really, haven't you people ever read a book? It'll be dark soon, and I'll come over and pick you up and we can shimmy the nodger.'

'Can we?' said Keith. 'Yes. With a hairpin,' said Malicia. 'I know it's possible, because I've read about it hundreds of times.'

'What kind of nodger is it?' said Maurice. 'A big one,' said Malicia. 'That makes it easier, of course.' She turned round abruptly and ran out of the stables. 'Maurice?' said Keith. 'Yes?' said the cat. 'What is a nodger and how do you shimmy it?'

'I don't know. A lock, maybe?'

'But you said-'

'Yes, but I was just trying to keep her talking in case she turned violent,' said Maurice. 'She's gone in the head, if you ask me. She's one of those people like… actors. You know. Acting all the time. Not living in the real world at all. Like it's all a big story. Dangerous Beans is a bit like that. Highly dangerous person, in my opinion.'

'He's a very kind and thoughtful rat!'

'Ah, yes, but the trouble is, see, that he thinks everyone else is like him. People like that are bad news, kid. And our

lady friend, she thinks life works like a fairytale.'

'Well, that's harmless, isn't it?' said Keith. 'Yeah, but in fairy-tales, when someone dies… it's just a word.' The No. 3 Heavy Widdlers squad were taking a rest, and they'd run out of ammunition in any case. No-one felt like going past the trap to the trickle of water that dripped down the wall. And no-one liked looking at what was in the trap. 'Poor old Fresh,' said a rat. 'He was a good rat.'

'Should've paid attention to where he was going, though,' said another rat. 'Thought he knew it all,' said yet another rat. 'A decent rat, though, if a bit smelly.'

'So let's get him out of the trap, shall we?' said the first rat. 'Doesn't seem right, leaving him in there like that.'

'Yes. Especially since we're hungry.' One of the rats said, 'Dangerous Beans says we shouldn't eat rat at all.' Another rat said, 'No, it's only if you don't know what they died of, 'cos they might have died of poison.' Another rat said, 'And we know what he died of. He died of squashing. You can't catch squashing.' They all looked at the late Fresh. 'What do you think happens to you, after you're dead?' said a rat, slowly. 'You get eaten. Or you go all dried up, or mouldy.'

'What, all of you?'

'Well, people usually leave the feet.' The rat who'd asked the question said, 'But what about the bit inside?' And the rat who'd mentioned the feet said, 'Oh, the squishy green wobbly bit? No, you ought to leave that, too. Tastes awful.'

'No, I meant the bit inside you that's you. Where does that go?'

'Sorry, you've lost me there.'

'Well… you know, like… dreams?' The rats nodded. They knew about dreams. Dreams had come as a big shock when they started to happen. 'Well, then, in the dreams, when you're being chased by dogs or flying or whatever… who is it that's doing that? It's not your body, 'cos that's asleep. So it must be an invisible part that lives inside you, yes? And being dead is like being asleep, isn't it?'

'Not exactly like asleep,' said a rat, uncertainly, glancing at the fairly flat thing formerly known as Fresh. 'I mean, you don't get all blood and bits sticking out. And you wake up.'

'So,' said the rat who'd raised the whole question about the invisible part, 'when you wake up, where does the dreaming part go? When you die, where does that bit that's inside you go?'

'What, the green wobbly bit?'

'No! The bit that's behind your eyes!'

'You mean the pinky-grey bit?'

'No, not that! The invisible bit!'

'How would I know? I've never seen an invisible bit!' All the rats stared down at Fresh. 'I don't like this kind of talk,' said one of them. 'It reminds me of the shadows in the candlelight.' Another one said, 'Did you hear about the Bone Rat? It comes and gets you when you're dead, they say.'

'They say, they say,' muttered a rat. 'They say there's a Big Rat Underground who made everything, they say. So it made humans, too? Must be really keen on us, to go and make humans too! Huh?'

'How do I know? Maybe they were made by a Big Human?'

'Oh, now you're just being silly,' said the doubting rat, who was called Tomato. 'All right, all right, but you've got to admit that everything couldn't have just, well, turned up, could it? There's got to be a reason. And Dangerous Beans says there's things we should do 'cos they're right, well, who works out what's right? Where does “right” and “wrong” come from? They say, if you've been a good rat, maybe the Big Rat has got this tunnel full of good eating that the Bone Rat will take you to'

'But Fresh is still here. And I ain't seen a bony rat!'

'Ah, but they say you only see it if it's coming for you.'

'Oh? Oh?' said another rat, nervous to the point of mad sarcasm. 'So how did they see it, eh? Tell me that! Life's bad enough as it is without having to worry about invisible things you can't see!'

'All right, all right, what's been happening?' The rats turned, suddenly incredibly pleased to see Darktan scurry up the tunnel. Darktan pushed past. He'd brought Nourishing with him. It was never too soon, he said, for a member of the squad to find out what happened to people who got things wrong. 'I see,' he said, looking at the trap. He shook his head sadly.

'What do I tell everyone?'

'Not to use tunnels that haven't been marked clear, sir,' said Tomato. 'But Fresh, well, he's not a… he never was a good listener. And he was keen to get on with it, sir.' Darktan examined the trap, and tried to keep his face fixed in an expression of confident purpose. It was hard to do it, though. He'd never seen a trap like it. It looked a really nasty one, a squeezer rather than a chopper. It had been put where a rat hurrying to the water would be bound to trip it. 'He's not going to do any more listening now, that's for certain,' he said. 'The face looks familiar. Apart from the bulging eyes and the tongue hanging out, that is.'

'Er, you talked to Fresh in the muster this morning, sir,' said a rat. 'Told him he was raised to be a widdler and to get on with it, sir.' Darktan's expression remained blank. Then he said, 'We've got to go. We're finding a lot of traps all over. We'll work our way back to you. No-one is to go any further along that tunnel, understood? Everyone say “yes, Darktan”!'

'Yes, Darktan,' the rats chorused. 'And one of you stand guard,' said Darktan. 'There could be more traps up that way.'

'What shall we do with Fresh, sir?' said Tomato. 'Don't eat the green wobbly bit,' said Darktan, and hurried off. Traps! he thought. There were too many of them. And too much poison. Even the experienced members of the squad were getting nervous now. He didn't like to come across unknown things. You found out what unknown things were when they killed you. The rats were spreading out under the town, and it was like no other town they'd found. The whole place was a rat trap. They hadn't found a single living keekee. Not one. That wasn't normal. Everywhere had rats. Where you got humans, you got rats. And on top of everything else the young rats were spending too much time worrying about… things. Things you couldn't see or smell. Shadow things. Darktan shook his head. There was no room in the tunnels for that sort of thinking. Life was real, life was practical, and life could get taken away really quickly if you weren't paying attention… He noticed Nourishing looking around and sniffing the air as they trotted along a pipe. 'That's right,' he said approvingly. 'You can't be too careful. Never rush in. Even the rat in front of you might have been lucky and missed the trigger.'

'Yes, sir.'

'Don't worry too much, though.'

'He did look awfully… flat, sir.'

'Fools rush in, Nourishing. Fools rush in…' Darktan could sense the fear spreading. It worried him. If the Changelings panicked, they'd panic as rats. And the tunnels in this city were no place for a terrified rat to be running. But if one rat broke ranks and ran, then most of them would follow. Smell held sway in the tunnels. When things went well, everyone felt good. When fear arrived, it flowed through the runs like flood-water. Panic in the rat world was a kind of disease that could be caught too easily. Things did not get any better when they caught up with the rest of the trap-squad. This time, they'd found a new poison. 'Not to worry,' said Darktan, who was worried. 'We've come across new poisons before, right?'