While his companions watched curiously, he shut his ears to the running fire of questions from Powers, squatted and drew a right angled triangle in the red desert sand. By one of the sides he drew three marks, by another four.
Then he stepped back and looked questioningly at the Martians.
One of the Martians squatted in a tangle of pipestem arms and legs, and with a long finger drew five lines beside the triangle's hypotenuse.
"They understand the Pythagorean theorem, sir!" exclaimed Von Frisch.
"Good! They undoubtedly know some astronomy, then. Go on."
Von Frisch hesitated a moment, then erased the triangle. He drew a small circle with rays from it, for the sun. He drew four larger concentric circles around it, with small circles for planets on the rim of each one.
He pointed to the third planet, then at himself, then at his companions, one by one. Then he pointed at the fourth planet and at the Martians, one by one. To complete the matter, he pointed at the sky.
"We are Earthmen," he said. "You are Martians."
The trouble was that the Earthmen didn't realize the things the Martians had were weapons until they used them. They didn't realize it then, as a matter of fact, because the Earthmen were dead, all three of them.
The Martian hunting party came back from the desert with word of the strange creatures who came, apparently, from another world.