little crater-island loomed here. I struggled after him. Then I saw that he had plunged into what seemed a water-filled little passage leading back under the island. I was there in a moment; tense, alert, cautious now that he might be crouching somewhere here in ambush. The ten foot high narrow passage wound up an ascent until unexpectedly my head broke the surface. I twitched off the helmet. I had thought that Tollgamo knew that he was being followed, but evidently he did not. Neck deep in water, I was near the rocky shore of a subterranean lagoon ... a huge jagged grotto here in the depths of the honeycombed little island. And then I saw Tollgamo. His helmet was off now. Carrying Nereid in his arms, he had mounted a broken rocky wall of the grotto, so that he was some fifty feet back and ten feet above me. I had kicked off my weighted shoes. I tried to dive, but I was discovered. Nereid gave a little cry; and as Tollgamo saw me, he suddenly checked his climb, set Nereid on her feet and held her against him. I had floundered forward, on the shore now; and dropped my knife, plucking a little ray-projector from my belt. Its fifty foot stab was ample here. Was Tollgamo armed? Brief thoughts; brief tableau. For that second he and Nereid stared down at me. A red glare painted them, a glare that came from what I saw now was a glowing pit almost beside them on this little volcanic island. In the heavy subterranean silence I could hear the low muttering, hissing rumble of the fires deep in the bowels of the earth, and the grotto was heavy with their sulphuric smell. A slow ironic smile was on Tollgamo's gray face, painted now by the red and yellow glare. "So, the Earthman!" he said. "And he finds Tollgamo unarmed." My little projector was leveled; but as he held Nereid against him I could not dare fire. He saw it, and his ironic smile broadened. Was he really unarmed? It seemed so. I could see the empty weapon-clips at his belt, from which evidently he had torn his exhausted weapons and flung them away. And his hands were both in plain view, gripping Nereid's shoulders. There was just a second when I saw his gaze flick from my leveled gun as he desperately measured his chances for escape. And then he seemed to reach his decision. The quiet smile still plucked at his thin gray lips. I must have made a move with my leveled muzzle; and suddenly it seemed to startle him. "Don't fire, Earthman!" he said sharply.