The Borribles retreated and took cover. Behind him Knocker could hear Adolf and Orococco and Sydney fighting for their lives; he saw the injured Vulge hobbling backwards and forwards between the two groups, gathering up as many lances as he could. On and on the battle raged, and more and more exhausted the Borribles became and still the Rumbles attacked. Before long all the defenders had been wounded at least superficially and Stonks received a lance thrust full in his thigh, and could no longer run in and out of the door, but threw his spears from the shelter of the hallway.

"Oh, for some stones," he kept muttering. "Oh, for a pile of stones as big as a house. I'd soon have my catapult twanging away like a banjo."

The Rumbles were nearer now. Their Warriors did not even bother to charge section by section, but stood their ground, throwing lances until they were wounded. Then another Rumble would step forward to take his fallen comrade's place. They fought with a silent hatred, and they did not lack courage. Knocker's arm was weary; he knew at last that he could not lift another spear, let alone throw it with any force.

"Knives out, lads," he said, and he and Stonks and Chalotte retreated into the hallway and found themselves back to back with Adolf, Sydney and Orococco. Beyond them Knocker saw hundreds of Rumbles, pushed along the corridor from behind by their bloodthirsty mates.

Vulge wedged himself into a little corner and wiped the long blade of his knife across his sleeve. "I like close work," he said and winced as the pain surged through his shoulder.

Then the Rumbles were all amongst them and there was a dreadful scrimmage in the hallway, but the attackers were not used to the kind of frenzied resistance put up by the desperate Borribles and under the cut and thrust of the knives they fell back momentarily.

"Oh, ho," yelled Adolf at the top of his voice. "This is cold steel and too close for comfort, eh? Adolf Wolfgang Amadeus Winston will account for at least a hundred of you. Come on! Come on! And he shouted and hooted and the others shouted and hooted with him, although their muscles ached and their eyelids smarted and the blood ran down their arms and legs from a thousand cuts.

But the Rumbles did not come again. Outside, where there had been a calm and cool dedication, was now all panic and shouts for help. Simultaneously, from the corridors came a surging waft of heavy air, followed by the muffled crump of a great explosion deep in the Bunker. A sheet of flame licked out of the tunnel, killing all that stood in its way. It touched but did not burn the battle-weary Borribles, but the blast of a solid wave of gas raised them from their feet and tossed them violently to the floor. The Rumbles in the Bunker had been silenced and the smell of singed fur and flesh floated over everything.

Stonks recovered first and getting to his hands and knees he crawled to the door. The Rumbles were still outside but a mighty swathe had been cut right through their ranks and the thing that had cut that swathe was a horse and cart. Sam was charging right through the massed Rumbles, and their fear of horses, their loathing of being munched up like a succulent truss of hay, had overcome their hatred of the Borribles and they had fallen back in panic.

"It's Sam," shouted Stonks to the others. "It's good old Sam."

Who knows what goes through the mind of a horse when he is left alone and is not working? Sam had spent the night dozing between the shafts of his cart and, when he had woken in the morning, he had missed the company and affection of the Borribles who had befriended him. There had not been a great deal of love in his life, none at all with Dewdrop, and he did not want to lose his new friends. He had munched a little grass but had found it dull and boring after the delicate flavour of the Rumble he had eaten, so he had pulled his cart to the edge of the copse and there he had gazed wistfully over the dank fields and sniffed. He hadn't smelt Borrible or even adult human but he had smelt Rumble. Sam had been tempted and had set off over the grass, he couldn't resist it. The smell had been so strong that he had imagined a whole meadow full of Rumbles and his imagination had been right. He saw the Rumbles, thousands of them, and with a snort and a stamp he had charged; the cart behind him had felt as nothing and the Rumbles melted away on his right and left. Then he heard a voice he recognised calling his name, calling it with thankfulness and love. Then more voices called out, and looking before him he saw his friends, penned into some kind of a hole set in the hillside, and all that lay between him and those friends were a few hundred Rumbles, so he charged again.

Knocker and the others crawled and dragged themselves to the edge of the Great Door and they saw a great clear road leading to the horizon. Sam came galloping down the slope and swung the cart round so it skidded to a halt alongside the doorway in a cloud of rain-spray.

"Oh," cried Sydney, tears of relief standing in her eyes. She ran to the horse and kissed him. "Good old Sam, you've saved us, all of us. Oh, Sam."

As quickly as they could the Borribles clambered into the cart. Vulge was pushed from below and pulled from above because his wounds had stiffened so much that he could not climb the cart-wheels unaided. Everyone was eager to get Sam on the move and escape to the streets; everyone that was except Knocker, who, with unbelievable single-mindedness, returned through the Great Door to retrieve the Rumble treasure box.

It was a foolhardy move. Smoke poured from the opening and the huge door-jambs were wilting and twisting under the effect of the immense heat. Once inside, Knocker found that the hallway was an inferno of flaming and falling timber; scorched bricks expanded and exploded from the walls like cannon shot. The Bunker ceiling drooped more every second as the whole Rumble edifice began to collapse, but Knocker heeded none of that and ran on, risking his life to get at the money.

Adolf and Orococco, against their better judgement, followed, not for the treasure, but to help Knocker if they could, for, in spite of his faults, they loved the chief lookout and were willing to risk their lives to save him.

Knocker came to the box all right, but he found it almost buried in fiery rafters and white-hot bricks. When he had kicked the box clear of debris, he discovered that it was incandescent, defiantly red and burning with a dangerous light. The handles were hot to the touch and the box itself would burn the skin of whoever tried to carry it, but Knocker grasped it and hauled the dreadful burden to his shoulders. The handle seared deep into the flesh of his palms and the brass-bound corners of the box smouldered through his clothing and down into his back. He staggered and slipped and Adolf caught him up and shoved him on towards the doorway that Knocker could not see in his pain.

Orococco yelled, "Over here, Knocker, damn you!" Then, "Watch out, Adolf!"

The warning came too late. A dying Rumble had risen to his knees unnoticed, and with a sticker in his grasp he fell against Adolf and brought him down. The German scrambled to his feet immediately, though the spear had snapped off in his right thigh. "Verdammt," he cried in agony and he pulled the broken shaft from his leg, kicked the Rumble in the head and killed him once and for all.

Orococco hurled Knocker from his path and ran towards the German who, blinded by the billowing smoke, was limping away from the heart of the fire.

"Adolf," he shouted, his heart breaking, "this way."

It was then that the ceiling of the hallway of the Great Door collapsed. With a roar like an avalanche the great red-hot timbers fell, bringing with them a lethal barrage of blazing stone. A molten, glowing wall reared up between Orococco and Adolf and the brave Totter was forced out of the smoking Rumble halls, his clothes aflame, his hair burning like a torch. Adolf was gone; lost in the heart of a volcano.

Once outside Orococco threw himself down and rolled over and over. Sydney jumped to the ground and beat him about the head to extinguish the flames that might have killed him. She helped him to his feet and he saw that Knocker, with the strength of a madman, was pushing the box up and into the cart. Chalotte leant over him, bashing at his smoking shoulders with the flat of her hand. An angry shout went up from the Rumbles. They had seen the box, and a shower of lances came over, some wounding the horse and making him lurch in the traces. Sydney and Orococco ran forward and, catching hold of the pain-crazed Knocker, they propelled him angrily aboard. Then Stonks stretched out a hand and helped them as they climbed up the spokes of the wheel.

"Where's Adolf?" screamed Chalotte. "Where's Adolf?"

"He's had it," said Orococco, his face tight with anguish. "The roof came down. I couldn't get to him. There's nothing we can do; we'll have to go. Nothing could live in there, nothing."

"You mean Adolf's been killed all because of a bloody box?" said Stonks. "What the hell's in it, anyway?"

Knocker jumped to his feet. "It's the Rumble treasure," he shouted, his eyes shining strangely with pain and something else. "It's money."

The others looked at him in horror and they knew then that Knocker had had a mission all along and hadn't told them; that Spiff had sent him to steal this treasure and take it home—and that for Knocker nothing else mattered.

"It is a bad thing, that box," cried Chalotte, "it has killed Adolf and will kill more of us. It's bad luck; throw it overboard."

"Yes," said Orococco, "that is enough. The Rumbles might let us go easier if they see we leave the money. We've done what we came to do. Let's get off while we still have a chance."

"No," roared Knocker, his hand falling to the bloody knife at his belt. He looked wild, his hat was gone and his hair swung over his eyes. "You've all got your names, but I will get a second one if I can get the box back to Battersea. It's going with me, I tell you, and I'll kill anyone who tries to stop me." And to put an end to the argument he picked up a stone from the bottom of the cart and threw it hard at Sam's hind-quarters and, with no need for guidance, the brave horse bore the Adventurers away from the shattered remains of the Great Door.

The Rumbles had been terrified by the precipitate arrival of Sam and his cart and had retreated in panic, but when they saw the treasure carried from the Bunker they were roused to action and advanced en masse to prevent, even now, the escape of the Borribles.