Sykes was ready with one of the crystal flasks as the boat was brought alongside, and McGuire followed with another. They took ten of the harmless-looking containers, and both men held their breaths as the boat grounded roughly on the boulder-strewn shore.
They lifted them out and bedded them in the sand, then returned to the submarine. This time Althora, too, stepped into the boat. They loaded in the balance of the containers; the motor purred. Another landing, and they stood at last on the island, where a mammoth tube towered into the sky and the means for its destruction was at their feet.
But there was little time; already the light was dimming, and the time for the firing of the big weapon was drawing near. The men worked like mad to carry the flasks to the base of the gun, where a dome of concrete marked the entrance to the rooms below.
Each man held a flask of the deadly fluid when Althora led the way where stairs went deep down into the earth under the domed roof. This part of the work had been foreseen, and the girl held a slender cylinder that threw a beam of light, intensely bright.
They found a surprising simplicity in the arrangements underground. Two rooms only had been carved from the solid rock, and one of these ended in a wall of gray metal that could be only the great base of the gun. But nowhere was a complication of mechanism that might be damaged or destroyed, nor any wiring or firing device.
A round door showed sharp edges in the gray metal, but only the strength of many men could have removed its huge bolts, and these two knew there must be other doors to seal in the mighty charge.
“Not a wire!” the scientist exclaimed. “How do they fire it?” The answer came to him with the question.
“Radio, of course; and the receiving set is in the charge itself; the barrel of the gun is its own antenna. They must fire it from a distance—back on the island where we were, perhaps. It would need to be accurately timed.”
“Come on!” shouted McGuire, and raised the flask of explosive to his shoulder.