"Tridium!" shouted the scientist. "You have discovered tridium!"
As in a dream, Dynamon saw the soldiers overpowering Mortoch and heard himself say, "What do you mean? Where is the tridium?" He stared about in wonder.
"The rock!" cried Thamon excitedly. "You touched the rock and were instantly insulated against the electric charge. Great heavens! What a discovery! Every one of these luminous rocks must be made of tridium."
Dynamon turned around and placed a hand on the glowing rock. Instantly, he felt himself enveloped in an extraordinary transparent aura.
"You see!" cried Thamon, and struck at the rock with his metal rod. Evidently, it was almost as soft as chalk, for several pieces as big as a man's fist chipped off and fell to the ground. Thamon stooped down and picked one of the pieces up and immediately he, too, stood in a curious, gleaming aura.
"It's tridium, all right!" exclaimed the scientist. "There can be no doubt about it. We knew it was on Saturn and we knew what its properties were, but we didn't know what it looked like. Do you realize what this means, Dynamon? It means that we may finally have found the defense against the Photo-Atomic Ray!"
Dynamon felt a little dizzy. Not only had he been snatched from what appeared to be certain death but he had inadvertently made a discovery that might save the people of the world from conquest at the hands of the Martians.
"Thamon, are you quite sure?" he said. "Are you quite sure that this will work against the Ray?"
"No," replied Thamon promptly. "I won't be quite sure until we've tested it out. From a theoretical standpoint, this glowing cloud, this aura that surrounds us as we touch a piece of tridium should insulate us against the Ray. But to be absolutely certain, somebody will have to expose himself to the Ray. Someone among us must go up to the surface holding a piece of tridium in his hand and face the Martians. If he is killed, then I'm wrong. But if he is not killed, then the Martians are at our mercy. We can walk up to them untouched and crush their egg-shell skulls with our bare fists."
"I see," said Dynamon gravely. "Then, one of us must be a heroic experimental guinea pig?"