The Walls of Air Page 0,60

familiar to her as the beating of her own heart - something she ought to recognize, but had not heard since...

... When? Puzzled, she rose and went to the wall opposite the door, where the soft thrumming seemed the loudest. She reached across the narrow workbench to place her fingers against the stone.

'Oh, my God,' she whispered as the realization struck her. Vistas of possibility for which she had been unprepared seemed to gape like chasms before her startled feet.

Aide saw the look in her eyes, snatched up the lamp, and came hastily to her side. 'What is it?

Gil turned her head to look at Aide, the chill grey of her eyes kindled almost to blue in the wavery glow. 'Feel the wall,' she whispered.

Aide obeyed, hesitating, and at once a frown of puzzlement that was half-fear and half-recognition touched her brow. 'I - I don't understand.'

Gil's voice was barely a breath, as if she feared to drown out that almost unheard sound. 'It's machinery.'

The trapdoor was not hidden, as Gil had feared it would be. It was merely set out of the way. The workbench, built centuries later, had been laid right across it. The hollow tube, like a wormhole through the darkness of the Keep's black wall, seemed to go up forever.

As she emerged at last into the vast space of warmth, dust,

and the soft, steady throbbing of metal and air, it was borne upon Gil that she had, indeed, crossed a threshold and entered realms unknown to anyone else in this world -including, she was positive, Ingold himself. It came to her that the Keep of Dare, far from being a simple stronghold, was in itself a riddle, as black and impenetrable as the Dark.

She reached down the shaft and took the lamp that Aide carried. As she held up that single point of brightness, dark shapes limned themselves from the blackness around her-monstrous pipes, oily and black and shining, coils of twisting cable strung like vines from the low ceiling, and the gaping maws of enormous ducts that breathed warm air like the nostrils of some inconceivable beast. The noise, though not loud, drummed into her bones like the beat of a massive heart.

Aide emerged from the ladder shaft and stared around at the labyrinthine vista, barely to be seen in its cloak of shadows, with huge and frightened eyes. Gil suddenly realized that she was dealing with someone who had been brought up at approximately a fourteenth-century level of technology - and of the nobility, at that. A few minutes ago, she had felt no difference between them, as if they were contemporaries. Now the gulf of time and culture yawned like a canyon. She herself, theoretically acquainted with Boulder Dam and the wonders of Detroit, was silent before that endless progression of lifts and screws and pipes whose shapes the lamplight only hinted at. To Aide it must be like another world. 'What is it? Aide whispered. 'Where are we?'

'At a guess,' Gil replied in tones equally soft, as if she feared to break the silence that lay on those stygian metal jungles, 'I'd say we're at the top of the Keep, up above the fifth level. That ladder in the shaft seemed to go on forever. And as for what it is...' She held up the lamp and sniffed at the faint oily smell of the place. There was no dust here, she noticed, and no rats. Only darkness and the soft, steady beating of the Keep's secret heart. 'It's got to be the pumps.' 'The what?'

Gil stood up and walked along the perimeter of the little

clearing by the trapdoor. The light in her hand played over sleek, shining surfaces, and the warm drafts stirred her coarse, straggling hair. 'Pumps to circulate air and water,' she said thoughtfully. 'I knew they had to exist somewhere.'

'Why?' Aide asked, puzzled.

'As I said, the air and water don't move themselves.' She stopped and bent down to pick up another white glass polyhedron from where it lay half-hidden in the shadows of a braided mass of coils as big around as her waist.

'But why wasn't any of this mentioned in the records?' Aide asked, from her perch on the edge of the trapdoor. 'That, as a very great man of my own world would say, is the sixty-four-dollar question.' Gil slipped around a massive pipe of smooth, black, uncorrupted metal and passed her hand across the mouth of a huge duct. Deep within its shadows she could