Knocker shivered at the awesome beauty of it. "Strike a light," he said, "what a place."

"Come on," Napoleon's voice was harsh, "get a move on."

Knocker jumped down into the boat and took up his oar.

"Row on," called Napoleon with venom. "This 'ere Wandle's the steepest river in London, like rowing up Lavender Hill it is, with the traffic against yer."

The Adventurers bent forward. Their hands were sore, their backs ached and the tensions of the night had exhausted them. With their eyes closing and their muscles burning they rowed on and on, across a windswept landscape with no trees or buildings, until, after Armoury Way, they came by the back-yards of factories to Young's Ram Brewery and at last they heard Napoleon's soft command.

"Hold it steady now, ship yer oars."

They relaxed and the boat came gently to rest. Behind them dawn was lying along the streets of Wandsworth like a tired animal and the straight sides of the buildings, raised up in smoky yellow bricks, towered into a dusty sky. And very high, one bright window of light showed where an early morning bus-driver grumbled his way from a warm bed into a cold kitchen.

Napoleon did not allow the crew to rest for long. "Right, you lot, we're here!" he said, a certain amount of satisfaction in his voice, and the Borribles turned and not one of them didn't gasp in horror. In a cliff-like factory wall a deep hole was visible: a brick culvert, barely large enough to allow the passage of the boat, hardly high enough to clear the heads of the rowers. It dripped with green slime and Napoleon's voice echoed feebly around it, dying weakly, sucked into nothing. The stench was disgusting and solid, rolling out onto the straggling river in misty clouds, like the final gasps of a decaying beast.

"Swipe me, man," said Orococco, his eyes and teeth looking green in the queer light that floated up from the water, "we ain't going in there, I hope."

Napoleon stood up in the prow, his legs spread, his hands on his hips, like a ruffian pirate captain. "This is the River Wandle," he said. "An ordinary little river that flows under the houses."

"It stinks," said Bingo.

"You've had it too easy," retorted Napoleon, "this is Wandsworth where the best Borribles come from."

Knocker grinned to himself in spite of the trepidation he felt in common with his companions. Whatever else he thought about Napoleon Boot he had to admit that the Wendle had guts and style.

"Now, we're taking this boat in," said the navigator, "and anyone who don't like it can swim home in this." He bent and scooped up a handful of the river water and cast it into the gangway of the boat. The eyes of the Borribles were attracted by the evil-looking liquid while their bodies were repelled by it. The water hardly disintegrated at all but green globules of it rolled into the crevices of the woodwork to lie there glowing.

"Right," went on Napoleon, crouching in the prow. "Gently . . . keep your heads down and I'll fend off with my hands."

Under the cautious power of the rowers the boat shoved its nose into the steaming dankness of the sewer and Napoleon shone his torch this way and that, but it did little good, for the rolling clouds of fog swallowed and digested the tiny beam before it could travel a yard. The rowers leaned back in their seats, digging their oars through the surface of the water. Adolf sat on the stern seat, shining his torch backwards, and in its light the Adventurers could see the dripping roof of the cavern and sometimes the gaping holes of side tunnels where thick water slid slowly out to fasten itself to the main stream. The German hummed gently to keep up their spirits. "Ho, ho, heave ho." Then he repeated it, "Ho, ho, heave ho. Come, my brothers, ho, ho, heave ho."

Napoleon's commands came regularly in a quiet voice. "Slowly bow side, two strokes. Easy stroke side, now one stroke." And so they groped forward, hesitating at times before tunnels that forked to right and left, Napoleon sometimes knowing where he was going, sometimes guessing.

After what seemed hours of paddling the oars stuck against the walls and they were brought into the boat. "It's too narrow for rowing now," said Napoleon. "Someone will have to get into the water and pull the boat along."

There was silence amongst the Borrible crew. Napoleon bent under a seat and pulled out a pair of rubber waders. He was laughing to himself as the others could see in the light of his torch.

"I knew I'd have to do it," he said. "The best Borribles come from Wandsworth all right."

Adolf chuckled. "Ho, I don't know about that, we've got a lot of dirty water in Hamburg, my friend. Give me the waders, I will pull you, I haven't done any of the rowing." The German bustled down the boat. He took the waders from the astonished Napoleon, slipped them on and jumped into the stream with no hesitation at all.

The rowers swivelled in their seats to watch with amazement. Bingo knelt and shone his torch just ahead of the intrepid little German, so that he could see where he was going, but Adolf had his own torch hooked onto a button of his jacket. He grabbed the painter in both hands and with a "Ho, ho, heave ho," he pulled the boat smartly along as if it weighed nothing.

"Well I never," said Sydney.

Napoleon shook his head. "There'll be a kind of pathway by the side of the sewer a little further on," he called, "then you'll be able to get up on that."

This information turned out to be true and soon Adolf was striding out cheerfully along a brick bank that had been built originally for the sewer-men of Wandsworth, the only adults that the Wandsworth Borribles respected.

Suddenly Adolf stopped humming and tugging simultaneously. The rope went slack and The Siver Belle Flower bumped into the bank. Those in the boat looked up to discover what had stopped the German and saw, crouching aggressively against the curving wall of the sewer, an armed Wendle.

He was a thin and wiry figure and he was wearing the same kind of rubber waders that Napoleon had lent to Adolf. Instead of the normal woollen Borrible cap this Wendle, like other warriors of his aggressive tribe, wore a metal helmet to cover his ears and guard his head; made from an old beer can, it glowed coppery green in the light of the torches. He wore a thick chunky jacket of wool covered with plastic to keep out the water and the plastic shone orange and luminous, like the coats worn by the men who work on motorways. In fact the material had been stolen from them. The Wendle's face was hard and tough, much tougher than Napoleon's even, and his eyes moved quickly. He was not afraid even though he was one against ten. With a shout he thrust forward with the Rumble-stick he bore in his hands.

It was then that Adolf showed what a redoubtable fighter he could be. Unarmed, he was not one to avoid a good fight; as he had said, he liked fighting. The spear jabbed towards him and he slid gracefully to one side, his body folding into the water. His companions, who had come to like and admire the German, sprang to their feet in dismay. But Adolf was down not out, for as he fell he went under the vicious weapon and caught hold of the Wendle's right foot. As soon as Adolf's feet touched the river bottom he yanked as hard as he could and the Wendle lost balance and landed flat on his back on the edge of the pathway, the spear shaken from his grasp. The German grabbed his opponent's head and pulled it brusquely into the water and shoved it under the filthy surface.

"Ho, ho, ho," he roared, his face bright with triumph and his blue eyes flashing like police beacons revolving.

There was a clatter further along the tunnel and three more Wendles appeared, armed with powerful catapults, raised and ready, aimed at Adolf.

Napoleon waved his arms and his torch. "A Wendle, a Wendle, a Wendle!" he shouted at the top of his voice. "Don't fire! Borrible! Adolf, let him up. Quick or you're as kaput as a kipper."

The German kept his eyes on the strung catapults and cautiously raised the limp body of his assailant from the black water. He held it in front of him like a shield and without being noticed, except by Knocker, who was now in the prow of the boat with Napoleon, he slid a catapult from the unconscious Wendle's pocket and secreted it in his own.

"Good work," said Knocker to himself, "that kraut's a real find."

One of the three Wendles called out in a harsh voice that came grating along the tunnel wall. "You, put that Wendle back on the path, the rest of you keep dead still. There's another fifty of us up round the next bend."

Adolf carried his burden to the bank and unceremoniously dumped it. Then he stood against the prow of the boat. Knocker was right behind him now and it was easy to slip a few catapult stones into the German's right hand which was held behind his back in the hope that someone would know what he wanted.

Napoleon shouted out anxiously, "I'm a Wendle myself, on the Great Rumble Hunt. Flinthead knows about it, hasn't he told you?"

"He's told us," came the answer, "but if you've drowned Halfabar then you're in serious trouble." One of their number now came forward and knelt beside the half-drowned Wendle. He turned the sodden body over and pummelled the water put of it, ascertaining that the warrior would be capable of many more fights in the future. He nodded to the others and they seemed satisfied.

When Halfabar had been placed in The Silver Belle Flower to recover, Adolf was permitted to continue pulling the boat.

"Walk in the river and follow us slowly," he was ordered, "and do everything we tell you. If any of you make a move towards a catapult, well . . . you'd better tell them what, you Wendle in the boat. We could starve you out without lifting a finger. There's fifty behind you now, as well as fifty in front."

Knocker glanced round, as did his friends, and figures appeared wading through the water behind them, perhaps more than fifty, all bearing Rumble-sticks. The Adventurers were hopelessly outnumbered, all they could do was obey.

"Who's the Borrible who's been doing all the talking?" Knocker asked Napoleon, who looked worried, as if the Wendles might take it out on him for this incursion.

"He's a two-name Borrible," whispered Napoleon, "but he's just called Tron. If he had a name for all the things he's done he'd be a hundred-name Borrible, I can tell you. Hard as nails he is, and Flinthead, our chief, why, he's just the same. Nobody comes in or out of here without their say-so."