Doc thought at first that they meant that Iwaldi's men had picked them up near the castle. But they said they had been digging in the woods near the bottom of the massive stone cap on which the castle rested. The earth had fallen in at the bottom of their trench, and they had gone in with it. Their shovels and picks had broken through the top of a tunnel. Exploring the tunnel, they found that it was part of an immense labyrinth of many levels.

They had pushed on, fascinated because they had come across stone figurines and the skeletons of men who were obviously early Palaeolithic. And then some men had captured them and brought them here, despite their protests. After a while, a strange long-bearded dwarf had appeared and questioned them. Barbara called him The Mountain King and said these were his halls.

'He wouldn't let us go,' she said. 'He - what'd you say his name was. Iwaldi? - said we were spies and that he'd kill us. But not before he found a use for us, since he didn't believe in wasting anything. He kept muttering something about the nine. Just the nine. Nine what?'

Doc did not reply. He entered the cell and prowled around with his detector in hand. Then he came out and said, 'If I were you two, I wouldn't report this to the local authorities. Or any authorities. I'd just quietly get out of Germany and get back to London. I know you can't forget this, but you should act as if you had.'

'Really?' Carlos Cobbs said. 'Why should we?'

'You would probably die very soon after you started to talk about this. There is another group which is out after Iwaldi's hide - and mine - which would shut you up the hard way. Hard for you, easy for them.'

'And who are you?' Barbara said.

'Your liberator,' Doc said. He was thinking that he should send a radio message to his cousin in London to check on these two as soon as he got back to the village. 'Barbara Villiers?' Barney said, smiling. 'An old and ... uh ... well-known name. You aren't related to the late Duchess of Cleveland, Countess Castlemaine, are you?'

The woman smiled back at him and became twice as beautiful. 'You mean the wicked woman who was born in 1641, the daughter of Viscount Grandison? The mistress of Charles II, John Churchill, and William Wycherley, not to mention others common and great?'

'Yes,' Barney said.

She laughed and said, 'Yes, I'm related to her. But I don't have a title. I'm just a commoner.'

'You're true royalty - aesthetically speaking,' Pauncho said.

Barney glared at him.

'Don't you wish you'd said that?' Pauncho said, sneering at Barney.

'We're going after Iwaldi,' Doc Caliban said. That'll be very dangerous. Besides, I don't want to have to worry about you when the fireworks begin. I suggest that you go back the way we came.'

'Won't that be dangerous, too?' Barbara said. She was looking him up and down and evidently liking what she saw. Doc felt uncomfortable and cursed himself for being weak enough to experience the feeling. He never got over it. He always attracted women, and he always felt uneasy at their admiration. What was worse, he now knew why he got uneasy, and he did not like that at all. After his final encounter with Lord Grandrith in that old castle in the Cumberland, when he had been invalided with a broken neck and was regrowing some rather roughly removed skin and flesh, he had done some deep self-probing.

'Either way is dangerous,' he said. 'But the trail blazed is always less dangerous than the trail to be blazed. Generally, anyway.'

She looked at Carlos Cobbs. 'I'd feel safer if we were with them even if we might run into that dirty old man and his gang.'

Carlos Cobbs shrugged. He said, 'Anything you say, my dear.'

'We can't spare any guns,' Doc said. Tick up one of those swords or an axe and stay well behind us.'

'Maybe one of us ought to stay close with the lady and see she doesn't Come to any harm,' Pancho said. He grinned at the titian-haired beauty and managed to look even more like a baboon.

'If she stays with you she will come to harm,' Barney said. 'Just looking at you is enough to bring anybody down with a fatal case of the uglies.'

Doc walked away with Barney and Pauncho a few steps behind and the couple following them. He halted before the archway, swept his detector back and forth, and then started through. He felt the floor dip and leaped high into the air like a scalded cat. The detector flew out of his hand as he grabbed for the rough stone along the edge of the point of the archway. Even though his leap took him above the heads of his two men, his fingers could not find a purchase on the stone. He fell back and into the hole below him and after Barney and Pauncho. Their yells were coming up the shaft even as he hurtled through the hole. He saw Cobbs and the woman staring open-mouthed and pale at him, and then the walls of the shaft were the only thing he could see.

Far below came a splash, then another splash. And then it was not so far below, and he plunged into icy water.

He went down deep, but his fall had been perhaps fifty feet, enough to kill a man if he struck the water at the wrong angle. His hard heavy boots took the major part of the energy of the impact. Even so, he was half-stunned. But he had secured the cap with the blacklight device onto his head by holding it with one hand, and he switched that on. Then he slipped his goggles down onto his eyes, sliding it over the skin to keep the water out, and held tightly with the other. As he rose toward the surface, he removed two plugs from a vest pocket and slipped these into his nose. He began breathing through them immediately. They strained oxygen from the water quite efficiently, and he breathed the carbon dioxide out through his mouth.

There was no light down here, and he would have been blind if it had not been for his black-light projector and goggles. Even so, the water seemed to have a suspension of plant growth or perhaps of dirt and he could not see far. But he did make out Pauncho's form and when he had swum near enough for Pauncho to see him, Pauncho gestured outward. Doc swam even closer and could then make out Barney's shadowy figure. In a moment, Barney had swum close.

Both had retained their caps with the projector and their goggles, and they had also inserted into their nostrils the filters. But the icy water was rapidly numbing them.

Doc reached into another pocket and removed an object the size and shape of a boy's marble. He popped it into his mouth, chewed on it, and then swallowed it. A minute later, he began to feel warm. The sense of disorientation that had started to slip through him disappeared. The pill not only provided a source of energy the output of which was proportionate to the demand for warmth, but it fought shock.

He reached the surface but could not stick his head into the air. The water at this point boiled into the ceiling of rock. He and his two colleagues could only stay under and let themselves be taken away by the powerful current. There was no use fighting against it. Even Doc Caliban's massive muscles, anchored to a skeleton almost twice as thick as a normal human being's, could not have made progress against that force.

For approximately five minutes, as registered by the hands of his wristwatch, they were swept between stone walls that came closer and closer. This narrowing of the channel also increased the power of the current. They sped by walls of granite worn smooth by other rocks tumbled along in the past by the river. They kept hold of each other's hand so they would not be separated, and they went around and around as if they were on a dancing streamer around a maypole. But then they began to get cold again, and they had to swallow another energon.

He had one pill left apiece. After the effect of that was gone, their chance for survival was small. Unless - At that moment he heard a roar, and suddenly the water was boiling. A sharp ridge of stone passed a few inches below his drawn-up legs, then he was sliding on an apron of slick rock and then he was half in the air, half in the water, falling and turning over and over. Pauncho's hand was torn from his; a second later, he struck something. His ribs hurt so much that he could not repress a gasp, and water choked him.