The swirling rain-clouds rushed on revealing the bright moon and the two Borribles dodged behind the bushes and kept as quiet as they could. There was danger in the air and they could feel it. It would pay to be cautious.

"Strewth," said Knocker, the chief skirmisher and lookout of the Battersea tribe, "what a bloody cheek, coming down here without so much as a by-your-leave."

Lightfinger, Knocker's companion, agreed. "Diabolical liberty I call it . . . nasty bits of work, covered in fur like nylon hearth rugs . . . snouts like traffic cones. Just like rats, aren't they?"

"There's a big one, just getting into the motor, he's shouting at the others, he's the boss all right. Tough-looking, do you see?"

"Yeah," answered Lightfinger, "they do what they're told, don't they? Look at them move."

Presently the two Borribles saw the large car drive away in the moonlight, passing along the shining tarmac which led between the trees to the limits of Battersea Park. The car stopped for an instant at the gates and then turned left into Albert Bridge Road and disappeared on its way southwards into the quiet streets of the outer London suburbs.

The two Borribles stood up and looked around. They weren't too happy in parks, being much more at ease in crowded streets and broken-down houses. It was only occasionally that the Borrible lookouts checked on the green spaces, just to see they were still there and that everything was as it should be.

When Knocker was sure they were alone he said: "We'd better see what they were up to over there. There's something going on and I don't like it."

All at once the patch of ground at his feet began to tremble and clumps of grass began to pop up and away from their roots. There was a noise too, a scraping and a scrabbling, and a muffled voice swore and mumbled to itself. The carpet of grass rose and fell violently until a squat protruberance established itself between turf and top soil. The bump hesitated, as if it didn't know whether to continue upwards or retreat downwards. It grunted, swore again and, as if undecided, took off on a horizontal course, forcing the turf up as it wriggled along.

At the first sign of trouble Knocker and Lightfinger had taken refuge behind a bush but as the bump moved away they came from cover and followed it.

"It's got to be . . ." said Knocker, "it can't be anything else, and down here in Battersea, it's bad, double bad."

The mound now stopped and shook and struggled and became bigger, and as it grew more clods of grass fell from it.

"Watch yourself," whispered Knocker, "it's coming out. Get ready to jump it."

Lightfinger and Knocker crouched, waiting with patience, their minds racing with schemes. The turf rose higher and higher till it was as tall as the Borribles themselves, then it burst and the grass fell away like a discarded overcoat and revealed a dark and sinister shape of about their own size.

It looked like a giant rat, a huge mole or a deformed rabbit, but it was none of these for it stood on its hind legs and had a long snout and beady red eyes, like the things that had gone away in the car.

Knocker gave a shrill whistle and at the signal both he and Lightfinger leapt forward. Knocker got an armlock round the thing's head and pulled it to the ground while Lightfinger fell onto the hairy legs and bent one over the other in a special lock that could dislocate a knee with no trouble. The thing shouted so loudly that it would have woken the neighbourhood if there'd been one in Battersea Park. Knocker squeezed it round the neck and whispered: "Shuddup, you great fool, else I'll smother yer." The creature shuddupped.

Knocker sat the prisoner up and got behind it so he could tie its arms back with a length of rope he took from his waist. He and Lightfinger were very careful with the animal because there was no telling how strong it was. Lightfinger moved so that he was sitting on the thing's legs, looking into the eyes, which were like marbles rolling around at the wide end of the snout.

"All right," said Knocker when he was ready, "give it a duffing."

Lightfinger grabbed it by the scruff of the fur and pulled its snout forward. "Name," he asked gruffly.

The snout moved a little and they heard a voice say in a distinguished tone: "Timbucktoo."

"Tim who?" asked Lightfinger again, shaking the snout good and hard.

"Timbucktoo."

"And where are you from, you moth-eaten carpet?" asked Knocker, though he knew the answer.

Timbucktoo shook himself free of the two Borribles and, though his hands were bound, he got to his feet and glared haughtily down his snout, his red eyes blazing.

"Why, I'm fwom Wumbledom of course, you dirty little tykes. You'd better welease me before you get into sewious twouble."

"I knew it," said Knocker turning to Lightfinger with excitement. "A Rumble from Rumbledom. Ain't it strange as how they can't pronounce their 'r's?"

"So that's a Rumble," said Lightfinger with interest. "I've often wondered what they looked like . . . bloody ugly."

"It's the first time I've been this close to one," said Knocker, "but you can't mistake them, nasty."

"You wevolting little stweet-awabs," exploded the Rumble losing his temper, "how dare you tweat me in this fashion?"

" 'Cos you're on our manor, that's how, you twat," said Knocker angrily. "I suppose you didn't even know."

"I only know what you are," said Timbucktoo, "and what I am and that I'll go where I like and do what I like without having to ask the permission of gwubby little ignawamuses like you. You'd better untie me, Bowwible, and I might forget about this incident."

"He's a real pain," said Lightfinger. "Let's throw him in the river."

The moon was clear of clouds again and glinted on the nearby Thames. In spite of himself the Rumble shivered. "That will do you no good. I can swim, you know, like an otter."

"So you should," said Knocker, "you look like one," and he cuffed the Rumble once more and told him to hold his tongue.

Knocker thought deeply, then he said, "I s'pose the river's the best idea for getting him off our manor, but maybe we ought to take him back and find out more about him, what his mob are up to. I don't like the look of it; suspicious this is, Rumbles down here in Battersea, it's wrong. We ought to give Spiff a chance to give this thing the once over."

"I think you're right, brother," said Lightfinger, and they hauled the Rumble to its feet and pushed it towards the Park Gates. When they reached the sleeping streets they kept to the dark shadows between the lamp-posts and marched rapidly in the direction of Battersea High Street.

Borribles are generally skinny and have pointed ears which give them a slightly satanic appearance. They are pretty tough-looking and always scruffy, with their arses hanging out of their trousers, but apart from that they look just like normal children, although some of them have been Borribles for years and years. They have sharp faces but their eyes are burning-bright and dart about all over the place, noticing everything and missing nothing. They are proud of their quickness of wit. In fact it is impossible to be dull and a Borrible because a Borrible is bright by definition. Not that they know lots of useless facts, it's just that they are quick and tend to dislike anyone who is a bit slow.

The only people likely to get close to Borribles are ordinary children because Borribles mix in with them to escape detection by "the authorities" who are always trying to catch them. Any child may have sat next to a Borrible or even talked to one and never noticed the ears because Borribles wear hats, woollen ones, pulled down over their heads, and they sometimes grow their hair long, hanging to their shoulders.

Normal kids are turned into Borribles very slowly, almost without being aware of it; but one day they wake up and there it is. It doesn't matter where they come from as long as they have what is called a "bad start". A child disappears from a school and the word goes round that he was "unmanageable"; the chances are he's off managing by himself. Sometimes it's given out that a kid down the street has been "put into care" because whenever he got home from school the house was empty; no doubt he's been Borribled and is caring for himself someplace. One day a shout might be heard in a supermarket and a kid with the goods on him is hoisted out by a store-detective. If that kid gets away he'll become a Borrible and make sure he isn't caught again. Being caught is the end for a Borrible.

So Borribles are outcasts but unlike most outcasts they enjoy themselves and wouldn't be anything else. They delight in feeling independent and free and it is this feeling that is most important to them. Consequently they have no real leaders, though someone may pop into prominence from time to time, perhaps because he has had a good idea and wants to carry it through. They manage without authority and they get on well enough together, though like everybody, they quarrel.

They don't get on with adults at all, or anybody else for that matter, and they say why should they? Nobody has ever tried to get on with them, quite the contrary. They are ignored and that suits them down to the ground because that way they can do what they want to do in their own quiet and crafty way.

Knocker and Lightfinger had been on night patrol in Battersea Park when they'd stumbled across the Rumbles and the discovery had annoyed and scared them. Borribles like to make sure that no other Borrible tribe is encroaching on their territory, that's bad enough. They are always frightened that they might be driven away from their markets and houses and have their little bit of independence destroyed, so scouting round the frontiers is a regular duty.

Unearthing a Rumble was something very upsetting. They are the real enemies of the Borribles and the Borribles hate them for their riches, their power, their haughtiness and their possessions. If the Rumbles were coming all the way down from Rumbledom to colonise the Park, what price Battersea High Street?

Knocker and Lightfinger harried Timbucktoo along in front of them. They went past Morgan's Crucible Factory, along Battersea Church Road and by St Mary's down by the river, and then into the High Street. They saw no one and no one saw them, it being well into the early hours of the morning. They made for an empty house standing opposite the end of Trott Street. It was tall and wide and the bottom windows were boarded up and a sheet of corrugated iron covered the main doorway. The facade of the building was painted over in grey, and in black letters was written, "Bunham's Patent Locks Ltd. Western 4828."