'Might have been your father who had his men working at this spot,' said the Professor thoughtfully. 'On the other hand, it may have been a band of nomads wintering here. It is a wild district, very sparsely inhabited, and droves of men do ride here and there, not always with the best intentions I fear. However, with the half-dozen soldiers Twang Chun was good enough to lend us, we should be secure, for he has seen that the men are really trained, and I think we can rely upon their courage.'
David never knew whether to admire the huge expanse of ruins, to which they had come, more when a wintry sun poured down upon them, or when the moon's cold beams swept softly over them. In any case, there was something fascinating and awe-inspiring about this lonely place. Standing on a huge sand-dune a few hundred yards from the edge of what had once been a big city, he would allow his mind free play at times, trying to imagine the place as it was when tenanted, when its broad streets hummed with human activity, when its battlemented walls frowned down upon all would-be intruders, and when its dwellings sheltered thousands of families long since gone and forgotten. And always his eyes would wander to the relics of a tower, once a stately edifice no doubt, which even now, thousands of years after the chimneys of the city had grown cold and the streets had reverberated for the last time to the tread of inhabitants, was decidedly impressive. It seemed to beckon to him, to attract him strangely, as perhaps it had done his father. Once, since his arrival there, he had found his way across the ruins to that tower; for the feat was not impossible. Clambering up what appeared to be a breach in the rotting outer walls of the city--and who could say, since no history existed to tell of the doings in this part so long ago, that very breach might have been the undoing of the city? It may have given entry to a besieging army, and have resulted in the sacking and desolation of the place. David clambered over the sand swept into the breach and toiled over a sandy waste now piled into high pinnacles, and then drooping suddenly in a long line, where, no doubt, a street ran. Finding a way across this and others he at length arrived at a point within hailing distance of the tower. But to approach closer was impossible. A deep ditch surrounded it, with steeply sloping walls of soft sand, while on the far side a battlemented wall arose, tottering in parts, but strong and defiant in other directions.