six feet, two inches. The man was seven feet or more. Both wore the Martian outer robe. The girl flung hers back. Her limbs were encased in pseudomail. She looked, as all Martians like to look, a very warlike Amazon. But she was a pretty girl. She smiled at me with a keen-eyed, direct gaze.

"Mr. Dean said at breakfast that you were big and handsome. You are."

They were brother and sister, these Martians. Snap introduced them as Set Miko and Setta Moa—the Martian equivalent of Mr. and Miss.

This Miko was, from our Earth standards, a tremendous, brawny giant. Not spindly, like most Martians, this fellow, for all his seven feet in height was almost heavy set. He wore a plaited leather jerkin beneath his robe and knee pants of leather out of which his lower legs showed as gray, hairy pillars of strength. He had come into the salon with a swagger, his sword ornament clanking.

"A pleasant voyage so far," he said to me as he started his meal. His voice had the heavy, throaty rasp characteristic of the Martian. He spoke perfect English—both Martians and Venus people are by heritage extraordinary linguists. Miko and his sister Moa, had a touch of Martian accent, worn almost away by living for some years in Greater New York.

The shock to me came within a few minutes. Miko, absorbed in attacking his meal, inadvertently pushed back his robe to bare his forearm. An instant only, then it dropped to his wrist. But in that instant I had seen, upon the gray flesh, a thin sear turned red. A very recent burn—as though a pencil ray of heat had caught his arm.

My mind flung back. Only last night in the city corridor, Snap and I had been followed by a Martian. I had shot at him with a heat ray: I thought I had hit him on the arm. Was this the mysterious Martian who had followed us from Halsey's office?

V

Shortly after that midday meal I encountered Venza sitting on the starlit deck. I had been in the bow observatory; taken my routine castings of our position and worked them out. I was, I think, of the Planetara's officers the most expert handler of the mathematical calculators. The locating of our position and charting the trajectory of our course was, under ordinary circumstances, about all I had to do. And it took only a few minutes every twelve hours.

I had a moment with Carter in the isolation of his chart room.

"This voyage! Gregg, I'm getting like you—too fanciful. We've a normal group of passengers apparently, but I don't like the look of any of them. That Ob Hahn, at your table—"

"Snaky looking fellow," I commented. "He and the Englishman are great on arguments. Did you have Princes' cabin searched?"

My breath hung on his answer.

"Yes. Nothing unusual among his things. We searched both his room and his sister's."

I did not follow that up. Instead I told him about the burn on Miko's thick arm.

He stared. "I wish we were at Ferrok-Shahn. Gregg, tonight when the passengers are asleep, come here to me. Snap will be here, and Dr. Frank. We can trust him."

"He knows about—about the Grantline treasure?"

"Yes. And so do Balch and Blackstone." Balch and Blackstone were our first and second officers.

"We'll all meet here, Gregg—say about the zero hour. We must take some precautions."

Then he dismissed me.

I found Venza seated alone in a starlit corner of the secluded deck. A porthole, with the black heavens and the blazing stars was before her. There was an empty seat nearby.

She greeted me with the Venus form of jocular, intimate greeting:

"Hola-lo, Gregg! Sit here with me. I have been wondering when you would come after me."

I sat down beside her. "Why are you going to Mars, Venza? I'm glad to see you."

"Many thanks. But I am glad to see you, Gregg. So handsome a man. Do you know, from Venus to Earth, and I have no doubt on all of Mars, no man will please me more."

"Glib tongue," I laughed. "Born to flatter the male—every girl of your world." And I added seriously, "You don't answer my question. What takes you to Mars?"

"Contract. By the stars, what else? Of course, a chance to make a voyage with you—"

"Don't be silly, Venza."

I enjoyed her. I gazed at her small, slim figure reclining in the deck chair. Her long, gray robe parted by design, I have no doubt, to display her shapely, satin-sheathed legs. Her black hair was coiled in a heavy knot at the back of her neck; her carmine lips were parted with a mocking, alluring smile. The exotic perfume of her enveloped me.

She glanced at me sidewise from beneath her sweeping black lashes.

"Be serious," I added.

"I am serious. Sober. Intoxicated by you, but sober."

I said, "What sort of a contract?"

"A theater in Ferrok-Shahn. Good money, Gregg. I'll be there a year." She sat up to face me. "There's a fellow here on the Planetara, Rance Rankin, he calls himself. At our table—a big, good-looking blond American. He says he is a magician. Ever hear of him?"

"That's what he told me. No, I never heard of him."

"Nor did I. And I thought I had heard of everyone of importance. He is listed for the same theater I am. Nice sort of fellow." She paused, then added, "If he's a professional entertainer, I'm a motor oiler."

It startled me. "Why do you say that?"

Instinctively my gaze swept the deck. An Earth woman and child and a small Venus man were in sight, but not within earshot.

"Why do you look so furtive?" she retorted. "Gregg, there's something strange about this voyage. I'm no fool, nor you, so you must know it as well as I do."

"Rance Rankin—" I prompted.

She leaned closer toward me. "He could fool you. But not me—I've known too many magicians." She grinned. "I challenged him to trick me. You should have seen him evading!"

"Do you know Ob Hahn?" I interrupted.

She shook her head. "Never heard of him. But he told me plenty at breakfast. By Satan, what a flow of words that devil driver can muster! He and the Englishman don't mesh very well, do they?"

She stared at me. I had not answered her grin; my mind was too busy with queer fancies. Halsey's words: "Things are not always what they seem—" Were these passengers masqueraders? Were they put here by George Prince? And then I thought of Miko the Martian, and the burn upon his arm.

"Come back, Gregg! Don't go wandering off like that!" She dropped her voice to a whisper. "I'll be serious. I want to know what in hell is going on aboard this ship. I'm a woman and I'm curious. You tell me."

"What do you mean?" I parried.

"I mean a lot of things. What we've just been talking about. And what was the excitement you were in just before breakfast this morning?"

"Excitement?"

"Gregg, you may trust me." For the first time she was wholly serious. Her gaze made sure no one was within hearing. She put her hand on my arm. I could barely hear her whisper: "I know they might have a ray upon us. I'll be careful."

"They?"

"Anyone. Something's going on. You know it. You are in it. I saw you this morning, Gregg. Wild-eyed, chasing a phantom—"

"You?"

"And I heard the phantom! A man's footsteps. A magnetic, deflecting, invisible cloak. You couldn't fool an audience with that, it's too commonplace. If Rance Rankin tried—"

I gripped her. "Don't ramble, Venza! You saw me?"

"Yes. My stateroom door was open. I was sitting with a cigarette. I saw the purser in the smoking room. He was visible from—"

"Wait! Venza, that prowler went through the smoking room!"

"I know he did. I could hear him."

"Did the purser hear him?"

"Of