But Slag and York had fallen into that flame, unable to halt their forward impetus. The green flame touched them first, and destroyed them. They were dwarf and ape one moment, nothingness the next. Watching from a slit in the tower wall, Karola rubbed tears from her wet cheeks with the back of her hand. * * * * * Far beneath him, the floor of the cave was dark and broken. There on the stone bridge, with the jewel-embossed roof so near, Thor was in a different world. He stood now on the tip of the bridge's arc. The thin crust of roof was within reach of his axe. Thor looked down, full into the red quartz oval where green Aava slumbered, moving and radiating always. "He's at the settlement. He's blasting away at something," Thor whispered. He swung the axe in circles. He stood on tiptoes and the muscles of his naked back and thickly thewed arms bunched and bulged. With a sob of fury, Thor drove his axe at the crust of roof. Sparks glinted. A flake of quartz fell away, dropped to the floor below and bounded. Echoes sprang up, dancing the length of the cave. Thor attacked the roof with insane fury. Flakes and chips of roof showered below, all along the cave-floor. Thor sobbed with the strain of his eerie battle. His lungs heaved. His arm rose and fell, rose and fell. Sparks grew to myriad thousands as the keen edge of the war-axe bit and dug in the stone. Over the clatter and clang of steel and stone, rose an ominous thunder. Aava was being awakened from his slumbers. The green of the cave grew brighter, more freshly verdant. The red of the carnelians became purple; the purple of the amethysts, black. Thor slashed and cut unceasingly. Like a volcano gathering itself to spew its lava, Aava rumbled. With fire and with fury, he quested for the source of the falling rock. A tongue of flame leaped up to stand for one long instant beside Thor. He grimaced and drove his axe without stay. The keen biting edges would not last long, now. They were almost done. A streak down the flat side of one axe-blade told him it would give, soon. And the roof showed no sign of cracking! * * * * * The men and women in the tower watched the circle of urns gathering around them, tilting upwards. Hugging the walls and shadows of the buildings, the androids watched. Arrows thudded down onto the androids attending the urns. But when two fell, four leaped from the darkness to take their places. High in the tower, Peter Gordon fed his arrows to the attackers. The string of his bow was warm. His fingers were blistered, raw with continual friction. But his lips were tight, and his pale blue eyes were icy. Karola bit her full red lower lip, shaking her long yellow hair from her eyes and wiping those same eyes surreptitiously with the palm when they grew moist.