There was something in his tone which made Kreynborg turn. And Thorn held a little forked stick in his hand.
"Turn off the induction-screen, or I kill you!"
Kreynborg looked at him and chuckled.
"It is bluff, my friend," he said dryly. "I haff seen many weapons. I am a scientist! You play der game of poker. You try a bluff! But I answer you with der heat-ray!"
He moved his great bulk, and Thorn released his left hand. There was a sudden crack on Kreynborg's side of the room. A pebble a little over an inch in diameter fell to the floor. Kreynborg wavered, and toppled and fell. Three times more, his face merciless, Thorn drew back his arm, and three times Kreynborg's head jerked slightly. Then Thorn faced the panel on which the induction-screen switch was placed. Several times he thrust his hand through the screen and abruptly drew it back with pain, in an attempt to throw the switch. At last he was successful, and now he walked calmly across the room and bent over the motionless Kreynborg.
"Skull fractured," he said grimly. "All right, Sylva."
He went through the narrow doorway beyond, picking up the pocket-gun as he went. There was a noise of whining machinery. Now Thorn was emptying pellets into the mechanism that controlled the dome of force. There was a crashing of glass. It stopped. There were blows and thumpings. That noise stopped too.
Thorn came back, his eyes glowing. He flung open the outer door of the rocket-ship, and Sylva went to him.
He pointed.