And now, in that rise of masonry to which his eyes had been so irresistibly drawn, there appeared the outline of a titanic arch not unlike that which he thought he had glimpsed so long ago in that cave within a cave, on the far, unreal surface of the three-dimensioned Earth. He realized that he had been using the silver key—moving it in accord with an unlearned and instinctive ritual closely akin to that which had opened the Inner Gate. That rose-drunken sea which lapped his cheeks was, he realized, no more or less than the adamantine mass of the solid wall yielding before his spell, and the vortex of thought with which the Ancient Ones had aided his spell. Still guided by instinct and blind determination, he floated forward—and through the Ultimate Gate.