During the night of 19-20 April the new development occurred. Gilman was half involuntarily moving about in the twilight abysses with the bubble-mass and the small polyhedron floating ahead when he noticed the peculiarly regular angles formed by the edges of some gigantic neighbouring prism-clusters. In another second he was out of the abyss and standing tremulously on a rocky hillside bathed in intense, diffused green light. He was barefooted and in his nightclothes, and when he tried to walk discovered that he could scarcely lift his feet. A swirling vapour hid everything but the immediate sloping terrain from sight, and he shrank from the thought of the sounds, that might surge out of that vapour.