Briden pushed at the stone in several places without result. Then Donovan felt over it delicately around the edge, pressing each point separately as he went. He climbed interminably along the grotesque stone molding—that is, one would call it climbing if the thing was not after all horizontal—and the men wondered how any door in the universe could be so vast. Then, very softly and slowly, the acre-great panel began to give inward at the top; and they saw that it was balanced.