“It was carved less than a year ago!” he said. His pulses suddenly hammered. “Simon, Carlin knew the old language! He had me teach it to him, remember!”

“You mean — Carlin carved this one?” Otho exclaimed.

“Read it!”cried Grag.

Curt Newton read aloud, “To the Futuremen, if they ever come — I have discovered an incredible secret, the strangest form of life ever dreamed. The implications of that secret are so tremendous that I am going to investigate them first hand. If I do not return be warned that the old citadel beyond the Belt holds the key of a staggering power.”

CHAPTER II

Citadel of Mystery

AS the echoes of Curt Newton’s voice died away the four looked at each other in troubled wonder. The rank ferns drooped unstirring in the weird half-light over the broken arches and falling colonnades. Somewhere in the jungle a beast screamed harshly with a sound like laughter.

Otho finally broke the silence. “What could Carlin have found?”

“Something big”, Captain Future said slowly. “So big that he was afraid of anyone else finding it. That’s why he wrote this in the language of the Old Empire that no one but Simon and I could read.”

Simon said practically, “The Belt is what the natives call the strip burned out by the Beam, isn’t it? Well — we can soon find out.”