Kerim Shah was hurrying up the slope, his hill-men behind him in a straggling crescent. They loosed as they ran, their arrows splintering against the walls or arching over the parapet.
The heavy teak portal gave way beneath the Cimmerian's assault, and he peered inside warily, expecting anything. He was looking into a circular chamber from which a stair wound upward. On the opposite side of the chamber a door gaped open, revealing the outer slope—and the backs of half a dozen green-robed figures in full retreat.
Conan yelled, took a step into the tower, and then native caution jerked him back, just as a great block of stone fell crashing to the floor where his foot had been an instant before. Shouting to his followers, he raced around the tower.
The acolytes had evacuated their first line of defence. As Conan rounded the tower he saw their green robes twinkling up the mountain ahead of him. He gave chase, panting with earnest blood-lust, and behind him Kerim Shah and the Irakzai came pelting, the latter yelling like wolves at the flight of their enemies, their fatalism momentarily submerged by temporary triumph.
The tower stood on the lower edge of a narrow plateau whose upward slant was barely perceptible. A few hundred yards away this plateau ended abruptly in a chasm which had been invisible farther down the mountain. Into this chasm the acolytes apparently leaped without checking their speed. Their pursuers saw the green robes flutter and disappear over the edge.
A few moments later they themselves were standing on the brink of the mighty moat that cut them off from the castle of the Black Seers. It was a sheer-walled ravine that extended in either direction as far as they could see, apparently girdling the mountain, some four hundred yards in width and five hundred feet deep. And in it, from rim to rim, a strange, translucent mist sparkled and shimmered.
Looking down, Conan grunted. Far below him, moving across the glimmering floor, which shone like burnished silver, he saw the forms of the green-robed acolytes. Their outline was wavering and indistinct, like figures seen under deep water. They walked in single file, moving toward the opposite wall.
Kerim Shah nocked an arrow and sent it singing downward. But when it struck the mist that filled the chasm it seemed to lose momentum and direction, wandering widely from its course.
'If they went down, so can we!' grunted Conan, while Kerim Shah stared after his shaft in amazement. 'I saw them last at this spot—'
Squinting down he saw something shining like a golden thread across the canyon floor far below. The acolytes seemed to be following this thread, and there suddenly came to him Khemsa's cryptic words—'Follow the golden vein!' On the brink, under his very hand as he crouched, he found it, a thin vein of sparkling gold running from an outcropping of ore to the edge and down across the silvery floor. And he found something else, which had before been invisible to him because of the peculiar refraction of the light. The gold vein followed a narrow ramp which slanted down into the ravine, fitted with niches for hand and foot hold.