But the little man was wringing his hands in exasperation. "Now, I declare!" he cried. "All this time, you have been opening and closing your mouths while we were communicating, and I thought it was caused by some physical disturbance! You use vocal converse, too!"
"But of course," said the girl.
"It is quite unnecessary!" snapped the scientist. "With the menaudo, I can understand your thoughts clearly—and communicate my own to you, as well. In the future, both of you will be kind enough to think without speaking!"
"Why?" asked Larry bluntly. "Miss Day and I aren't mind-reading big-brains like you. If we wish to speak to each other—"
For the first time since they had met him, Harg's ever-present smile faded. A trace of his annoying superiority, self-confidence, seeped away. In his eyes there was a groping expression oddly akin to fear.
"There is nothing you need tell her!" he ordered. "I do not care to risk my—" He stopped suddenly, cannily. When he spoke again, it was in a milder tone. "You may, if you wish, converse with your mouths when I am not present. But in my presence I require you to think your conversation."
A sudden suspicion began to form in Larry's mind. He stifled it instantly; thrust it from him lest Harg grasp that faint, half-formed thought. Hastily he changed the subject.
"This other beast—" he began aloud. Then, remembering Harg's warning, he stopped and rephrased the query in his mind. "This other strange beast," he thought. "What is it?"
He knew, then, why Harg had taunted him for his interest in the mechanism of the door. For swift as an arrow the answer formed itself in his brain.
"A phoenix," replied Harg, "of the late Stone Age. A most curious creature; half animal, half bird. Originally it was a native of the planet Mars. It adapted itself to utter cold and airlessness when that planet's atmosphere waned. A few phoenix migrated to Earth, but failed to survive in our heavy atmosphere."