Blake was still dazed at the cataclysmic suddenness of Mapes' death as Zehru swung the tube around to train it upon him. Only a last-minute desperate effort upon Blake's part saved him. His wildly thrown metal club made a lucky hit on the tube itself, knocking it, shattered and useless, out of Zehru's grasp. Unarmed, Zehru faced Blake with his face contorting in agony. For a moment the Xollarian swayed there, apparently trying to gather his failing strength for the next move. The deadly air of the enclosure was already taking hideous toll. The scaly flesh of his head and face was dissolving like melting butter. Zehru's strength was ebbing too swiftly for him to have any chance of gaining safety through either of the distant side walls. His only hope of fighting back to the purple mists was to pass Blake and go through the nearby end wall through which he had originally been drawn. He came lunging forward in an attack whose sheer fury made Blake give ground before the menace of the lashing tentacles. * * * * * Blake took another backward step, then staggered as his foot struck a rough spot in the ground. Zehru's tentacles were upon him before he could recover himself. His club was jerked from his fingers and sent hurtling far out of reach. Half a dozen of the tentacle-arms lashed around his throat in a strangling grip. He clawed wildly at the choking coils, but they failed to loosen even a fraction of an inch. Desperately Blake sent his fists smashing into the gray face. The scale armor of Zehru's skull, fast weakening in the liquefying influence of the oxygen, gave way beneath that battering attack. He staggered, and his coiling tentacles relaxed slightly. Blake tore himself free. A final smashing blow, with every ounce of his one hundred and ninety pounds behind it, sent Zehru crashing to the ground. The Xollarian tried to rise, then feebly slumped back, his strength spent. Blake leaped forward to finish his opponent, but stopped as he saw that his efforts were not needed. The deadly air of the enclosure was now overwhelming Zehru with swift and hideous death. He was literally rotting before Blake's horrified eyes, the gray-scaled skin sloughing off in streaming rivulets of pallid ooze, and the entire body contorting in what was obviously a death agony. Sickened, Blake stepped back a pace or two. Zehru's tentacles feebly beat the ground around him, then suddenly one of the writhing arms blundered upon a thin cable running along the ground. Before Blake could spring forward to stop him, Zehru with a last surge of power ripped the fragile metal strand completely in two.