instruments. But this little Rissman flier will never run them down when they have that much of a start.”
Curt was not as calm as his tanned, set face indicated. No more than any other man did Captain Future enjoy having his life threatened from ambush. But he was not one to let anger cloud his judgment. He led the way back to the jewel vault. Otho was still cursing audibly. Harrison Yale sprang to their side as they entered.
“The space stone?” cried the millionaire collector anxiously.
“They got it,” Curt gritted. “There was someone in this room when we entered. He grabbed the jewel from my hand.”
Yale stared. “Why, nobody could have been in this room when we entered. We’d have seen him.”
“Then it was somebody we couldn’t see,” Curt said.
“You mean somebody has an invisibility secret like yours, Chief?” Otho blurted.
“No. It wasn’t quite invisibility. I could glimpse him as a sort of vague, flying shadow. It was someone who couldn’t be seen as long as he crouched motionless against the wall — someone like that Chameleon Man in the freak-show tonight.”
Before the android could speak, Curt went on rapidly.
“This mystery is far bigger than I dreamed. It’s no mere theft of space stones for their commercial value. I learned that while I was examining that incredible gem.” He turned to Yale. “I’m afraid I can’t promise the return of your space stone, but I’m going to do my best to run down the robbers. Come on, Otho. We’ve got to hurry.”
Chapter 5: Home to the Moon
WHEN they were in the little Rissman flier, rocketing back to New York through the moonlit night, Otho asked eagerly:
“What’s up, Chief? Are we really going to hit the space trail again?” A gleam lit Otho’s eyes.
“We are,” Curt said grimly. “And I have an idea that for once you may get your fill of danger.”
He made no further explanation until they were back in Lester’s study in the Institute of Interplanetary Science. Then, to Ezra Gurney and Joan and the Police commander, Curt spoke rapidly.
“There’s hell behind these space stone robberies. Those seven jewels contain a tremendous secret. If my guess is right, each stone contains a part of the secret.”
“How in time could seven jewels hold a secret?” Ezra asked.
“It’s recorded in the space stones by mental transcription,” Curt declared. He smiled at their puzzled faces. “Psychologists discovered, a long time ago, that thought is really an electrical vibration of the brain’s electro-chemical neuron pattern. It can be transcribed in a permanent record like sound or light. Various substances will take a thought transcription, and play it back when hard radiation stimulates the record.
“It appears that the complex carbon isotope which forms a space stone will take a thought transcription. Examining Yale’s gem with X-rays before it was snatched from me, I received the thought record in it. I am sure now that the other six space stones have similar thought records in them, together forming one vast secret.”
Otho uttered an excited yelp and pointed to the small X-ray projector that stood on Kenneth Lester’s desk.
“Look, Chief! Lester was using that projector! I’ll bet he was using it to examine the space stone he had and accidentally got the thought record in it.”
“Just what did you hear in the thought message of the stone you examined?” Joan Randall asked.
“ ‘Thus had I put my own people in danger, for they wished me to lead them back whence I came. I pretended to agree, and —’ ” Curt went on to the end of the message, word for word.
“What does it mean?” old Ezra queried puzzledly.
“It doesn’t mean much without the parts of the secret that go before it and after it,” Curt Newton admitted.
“Then how the devil do you know that this secret is such a tremendously important one?” Otho demanded skeptically.
“Any of you ever hear of Thuro Thuun?” Curt