nd then—the miracle! Dick gasped in sheer delight as he realized that he had made no mistake.
At first all he could see was a number of criss-crossing phosphorescent lines that appeared shimmering through the blackness underneath. They ran luminously here and there, forming no particular pattern, much like the figures on the radium dial of a watch when first they come into wavering visibility at night.
Then the lines began to intersect one another, to assume geometric patterns and curves. And bit by bit they took meaning and significance.
And suddenly the whole invisible stronghold lay revealed upon the ground beneath, a shining, dazzling play of weaving light.
Buildings and hangars stood out, clearly revealed; the rounded vault of a dirigible hangar, and the shining ribbon of a road that ran through a pitch-dark tarmac, and was evidently constructed from some gas-impregnated materials. On this tarmac was a flight of shining airplanes, ready to take off. There were the odd, ovoid figures of the aviators in their silken overalls. More figures appeared, running out from the buildings. It was clear that the sudden raid had taken them all by surprise.
Luke Evans yelled and pointed. "We've got them now, sir!" Dick heard above the whine of the helicopter engine. "We've—"
But of a sudden the old man's voice died away, though his mouth was still moving.
Dick leaned out of his cockpit and fired a single red Very light, the signal for the attack. And from each plane of his flight, beneath him, a bomb slid from its rack and went hurtling down upon the gang below, while the airplanes circled and hovered, each taking up its station.