murmurs.
Gamma rays! Snap sprang to the dials. The direction and strength were soon obvious. A richly radioactive ore body was concentrated upon this hemisphere of the Moon! It was unmistakable.
"He's got it, Gregg! He's—"
The tiny grids began quivering. Snap exclaimed triumphantly, "Here he comes! By God, the message at last!"
Snap decoded it.
Success! Stop for ore on your return voyage. Will give you our location later. Success beyond wildest hopes.
Snap murmured, "That's all. He's got the ore!"
We were sitting in darkness, and abruptly I became aware that across our open window, where the insulation barrage was flung, the air was faintly hissing. An interference there! I saw a tiny swirl of purple sparks. Someone—some hostile ray from the deck beneath us, or from the spider bridge that led to our little room—someone out there was trying to pry in!
Snap impulsively reached for the absorbers to let in the outside light. But I checked him.
"Wait!" I cut off our barrage, opened our door and stepped to the narrow metal bridge.
"You stay there, Snap!" I whispered. Then I added aloud, "Well, Snap, I'm going to bed. Glad you've cleaned up that batch of work."
I banged the door upon him. The lacework of metal bridges seemed empty. I gazed up to the dome, and forward and aft. Twenty feet beneath me was the metal roof of the cabin superstructure. Below it, both sides of the deck showed. All patched with moonlight.
No one visible down there. I descended a ladder. The deck was empty. But in the silence something was moving! Footsteps moving away from me down the deck! I followed; and suddenly I was running. Chasing something I could hear, but could not see. It turned into the smoking room.
I burst in. And a real sound smothered the phantom. Johnson the purser was sitting here alone in the dimness. He was smoking. I noticed that his cigar held a long frail ash. It could not have been him I was chasing. He was sitting there quite calmly. A thick-necked, heavy fellow, easily out of breath. But he was breathing calmly now.
He sat up in amazement at my wild-eyed appearance, and the ash jarred from his cigar.
"Gregg! What in the devil—"
I tried to grin. "I'm on my way to bed—worked all night helping Snap."
I went past him, out the door into the main corridor. It was the only way the invisible prowler could have gone. But I was too late now—I could hear nothing. I dashed forward into the main lounge. It was empty, dim and silent, a silence broken presently by a faint click, a stateroom door hastily closing. I swung and found myself in a tiny transverse passage. The twin doors of A20 and A22 were before me.
The invisible eavesdropper had gone into one of these rooms! I listened at each of the panels, but there was only silence within.
The interior of the ship was suddenly singing with the steward's siren—the call to awaken the passengers. It startled me. I moved swiftly away. But as the siren shut off, in the silence I heard a soft, musical voice:
"Wake up, Anita, I think that's the breakfast call."
And her answer, "All right, George."
CHAPTER IV.
I did not appear at that morning meal. I was exhausted and drugged with lack of sleep. I had a moment with Snap to tell him what had occurred. Then I sought out Carter. He had his little chart room insulated. And we were cautious. I told him what Snap and I had learned: the rays from the Moon, proving that Grantline had concentrated a considerable ore body. I also told him of Grantline's message.
"We'll stop on the way back, as he directs, Gregg." He bent closer to me. "At Ferrok-Shahn I'm going to bring back a cordon of Interplanetary Police. The secret will be out, of course, when we stop at the Moon. We have no right, even now, to be flying this vessel as unguarded as it is."
He was very solemn. And he was grim when I told him of the invisible eavesdropper.
"You think he overheard Grantline's message? Who was it? You seem to feel it was George Prince?"
I told him I was convinced the prowler went into A20. When I mentioned the purser, who seemed to have been watching me earlier in the night, and again was sitting in the smoking room when the eavesdropper fled past, Carter looked startled.
"Johnson is all right, Gregg."
"Does he know anything about this Grantline affair?"
"No—no," said Carter hastily. "You haven't mentioned it, have you?"
"Of course I haven't. But why didn't Johnson hear that eavesdropper? And what was he doing there, anyway, at that hour of the morning?"
The Captain ignored my questions. "I'm going to have that Prince suite searched—we can't be too careful.... Go to bed, Gregg, you need rest."
I went to my cabin. It was located aft, on the stern deck, near the stern watch tower. A small metal room with a chair, a desk and a bunk. I made sure no one was in it. I sealed the lattice grill and the door, set the alarm trigger against any opening of them, and went to bed.
The siren for the midday meal awakened me. I had slept heavily. I felt refreshed.
I found the passengers already assembled at my table when I arrived in the dining salon. It was a low vaulted metal room with blue and yellow tube lights. At its sides the oval windows showed the deck, with its ports on the dome side, through which a vista of the starry firmament was visible. We were well on our course to Mars. The Moon had dwindled to a pin point of light beside the crescent Earth. And behind them our Sun blazed, visually the largest orb in the heavens. It was some sixty-eight million miles from the Earth to Mars. A flight, ordinarily, of some ten days.
There were five tables in the dining salon, each with eight seats. Snap and I had one of the tables. We sat at the ends, with the passengers on each of the sides.
Snap was in his seat when I arrived. He eyed me down the length of the table. In a gay mood, he introduced me to the three men already seated:
"This is our third officer, Gregg Haljan. Big, handsome fellow, isn't he? And as pleasant as he is good-looking. Gregg, this is Sero Ob Hahn."
I met the keen, somber gaze of a Venus man of middle age. A small, slim graceful man, with sleek black hair. His pointed face, accentuated by the pointed beard, was pallid. He wore a white and purple robe; upon his breast was a huge platinum ornament, a device like a star and cross entwined.
"I am happy to meet you, sir." His voice was soft and deep.
"Ob Hahn," I repeated. "I should have heard of you, no doubt, but—"
A smile plucked at his thin, gray lips. "That is an error of mine, not yours. My mission is that all the universe shall hear of me."
"He's preaching the religion of the Venus mystics," Snap explained.
"And this enlightened gentleman," said Ob Hahn ironically, nodding to the man, "has just termed it fetishism. The ignorance—"
"Oh, I say!" protested the man at Ob Hahn's side. "I mean, you seem to think I meant something offensive. And as a matter of fact—"
"We've an argument, Gregg," laughed Snap. "This is Sir Arthur Coniston, an English gentleman, lecturer and sky-trotter—that is, he will be a sky-trotter; he tells us he plans a number of voyages."
The tall Englishman, in his white linen suit, bowed acknowledgement. "My compliments, Mr. Haljan. I hope you have no strong religious convictions, else we will make your table here very miserable!"
The third passenger had evidently kept out of the argument. Snap introduced him as Rance Rankin. An American—a quiet, blond