The six of them hovered together close to the center of the huge emptiness of the Stadium; Dura felt cold and isolated despite the clamminess of the Pole. Ropes and guide rails were slung across the huge volume all around them, silent evidence of the crowds this place was designed to accommodate.

The Physician, Muub, was dressed in a severe, dark robe. As before, Dura found it impossible not to stare at the grand dome of his bald head. He greeted them with a smile which seemed professional enough but a little strained. "Thank you for your time."

Adda grinned. "Oh, we had a choice?"

Muub's smile thinned. Briskly he introduced his two companions: a Harbor supervisor called Hosch, cadaverously thin, who seemed to know Farr, judging from the sour glances he cast at the boy; and a tall, wispy tree-stem of a man called Seciv Trop whom Muub described as an expert on the Magfield. Like Muub's, Trop's fine old head was shaven, in the style of the academics of the University.

Muub rapidly sketched in the background to Hork's directive. "Frankly, I'm not certain about the value of this program; I may as well tell you that from the start. But I do sympathize with Hork's thinking." He looked about him, his expression hard. "I only need to be here, in the fragility of this Stadium, to recognize that we have to find some way to protect ourselves from the random danger of Glitches."

Dura frowned. "But why are we here? We Human Beings, I mean. You need experts. What can we possibly add?"

"Two things. One is that you are experts — or the nearest we have — on the Xeelee. So Hork believes, at any rate. And second, there's no one else." He raised his arms as if to embrace the City. "Dura, Parz may seem a large and rich place to you, but the economy has taken a severe battering from the Glitches. All our resources are devoted to coping with the consequences, to rebuilding the hinterland... all but us, and we are all Hork felt able to spare." He smiled at them. "Six of us, including a boy. And our mission is to save the world. Perhaps we will succeed; and what plaudits we will earn if we do."

He fell silent. The six of them hovered in a rough ring, studying each other warily — all but the Magfield expert Seciv Trop, who stared into the distance with his finely chiseled eyecups.