"There must be some way," Birrel said, striding around in an agony of frustration. "Some way. Some—listen, can you transmit visually, from world to world? Could you send a picture to Ruun?"
"Of course," said Shannock, rather shocked at his ignorance. "The interplanetary automatic relay system has been working ever since we learned how to build spaceships."
Then a queer look came over his face.
"You mean to transmit right from the cavern?"
"That would be proof enough, wouldn't it?" Birrel demanded. "If we showed them the actual cavern, down to the actual armaments?"
Looking a little stunned, Thile said it ought to be proof enough for anyone. "There's just one question. How are you going to do it?"
"Technically, can it really be done?"
"With a special type of transmitter, yes."
Birrel looked at the men of the underground. "If you'll help, we ought to be able to make a pretty good try. How many men can you muster in a hurry—armed?"