Secret of the Earth Star

The jewel glowed and death leaped from the gun
Secret of the EARTH STAR
HENRY KUTTNER
The theft of the Earth Star blazed a trail of death to a weird city under the Sahara.
Despite the blazing heat of the hot Indian night, this air-conditioned room in the palace was cool and comfortable. It was a bit too luxurious for a business office; otherwise, it might have been any New York suite. Three men sat at a small glass-topped table, on which stood a Gladstone bag.
They rose as two Indians entered, bowing respectfully to the Rajah. The latter was a small, weak-faced man with a straggling moustache and lips too large and red for his sallow face. He barely acknowledged the greetings, his gaze riveted on the leather bag.
“You have the Earth Star?” he asked.
“Yes,” said one of the three Europeans. He opened the bag, unlocked a metal case built into it, and withdrew a jewel-case. This he opened and placed flat on the table.
The Rajah’s mouth went dry. He could not repress a little shiver. “The Earth Star . . .” he whispered.
On black velvet the great gem flamed. It was lens-shaped and supernally lovely, with rays of living light flaming out from its heart. The colors latent within it changed and shifted under the soft illumination. It was like a diamond—yet no diamond had ever possessed the wonder of the Earth Star.
The Rajah’s secretary breathed deeply. “Carbon,” he murmured. “A tree-fern some million years ago—”
One of the Europeans interrupted, though he did not look away from the jewel. “A little more than that, sir. It took unusual pressure to make the Earth Star. It came from the new cavern mines under the Atlantic, you know, when they were taking cores to test from immense depths. A tree-fern made the Earth Star—but that fern was somehow buried deeper than man has ever thought possible. It’s immensely harder than diamond, though it’s carbon, of course. And the only one in existence—”