Brent, the chief officer, burst up the companion. His face was livid. "Black ship approaching us from the Moon, Sir," he stammered. "Benson's training his guns, but it must be twenty thousands miles away." "Yes, even our ray-guns won't shoot that distance," answered Nat. "Tell Benson to keep his guns trained as well as he can, and open fire at five hundred." Brent disappeared. Madge and Nat were alone on the bridge. Nat was shouting incomprehensible orders down the tube. He stopped and looked up. The shadow of the approaching ship had crossed the Moon's disk and disappeared. "Well, young lady, I think your goose is cooked," said Nat. "If I'm not mistaken, that ship is Axelson's, and he's on his way to knock us galley-west. And now oblige me by leaving the bridge." "I think he's a perfectly delightful character, to judge from that message he sent you," answered Madge, "and--" Brent appeared again. "Triangulation shows ten thousand miles, Sir," he informed Nat. "Take control," said Nat. "Keep on the gyroscopic course, allowing for aberrancy, and make for the Crater of Pytho. I'll take command of the guns." He hurried down the companion, with Madge at his heels. * * * * * The gunners stood by the ray-guns, three at each. Benson perched on a revolving stool above the batteries. He was watching a periscopic instrument that connected with the bridge dome by means of a tube, a flat mirror in front of him showing all points of the compass. At one edge the shadow of the black ship was creeping slowly forward. "Eight thousand miles, Sir," he told Nat. "One thousand is our extreme range. And it looks as if she's making for our blind spot overhead." Nat stepped to the speaking-tube. "Try to ram her," he called up to Brent. "We'll open with all guns, pointing forward." "Very good, Sir," the Cockney called back. The black shadow was now nearly in the centre of the mirror. It moved upward, vanished. Suddenly the atomic motors began wheezing again. The wheeze became a whine, a drone. "We've dropped to two thousand miles an hour, Sir," called Brent. Nat leaped for the companion. As he reached the top he could hear the teleradio apparatus in the wireless room overhead begin to chatter: "A-A-A. Don't try to interfere. Am taking you to the Crater of Pytho. Shall renew my offer there. Any resistance will be fatal. Axelson." And suddenly the droning of the motors became a whine again, then silence. Nat stared at the instrument-board and uttered a cry. "What's the matter?" demanded Madge. Nat swung upon her. "The matter?" he bawled. "He's neutralized our engines by some infernal means of his own, and he's towing us to the Moon!" * * * * *