He seemed a very little boy to be carrying so large a butterfly net. He swung it in his chubby right fist as he walked, and at first glance you couldn’t be sure if he were carrying it, or it carrying him.

He came whistling. All little boys whistle. To little boys, whistling is as natural as breathing. However, there was something peculiar about this particular little boy’s whistling. Or, rather, there were two things peculiar, but each was related to the other.

The first was that he was a Martian little boy. You could be very sure of that, for Earth little boys have earlobes while Martian little boys do not--and he most certainly didn’t.

The second was the tune he whistled--a somehow familiar tune, but one which I should have thought not very appealing to a little boy.

“Hi, there,” I said when he came near enough. “What’s that you’re whistling?”

He stopped whistling and he stopped walking, both at the same time, as though he had pulled a switch or turned a tap that shut them off. Then he lifted his little head and stared up into my eyes.

“‘The Calm’,” he said in a sober, little-boy voice.

“The what?” I asked.

“From the William Tell Overture,” he explained, still looking up at me. He said it deadpan, and his wide brown eyes never once batted.

“Oh,” I said. “And where did you learn that?”

“My mother taught me.”

I blinked at him. He didn’t blink back. His round little face still held no expression, but if it had, I knew it would have matched the title of the tune he whistled.

“You whistle very well,” I told him.

That pleased him. His eyes lit up and an almost-smile flirted with the corners of his small mouth.

He nodded grave agreement.

“Been after butterflies, I see. I’ll bet you didn’t get any. This is the wrong season.”

The light in his eyes snapped off. “Well, good-by,” he said abruptly and very relevantly.

“Good-by,” I said.

His whistling and his walking started up again in the same spot where they had left off. I mean the note he resumed on was the note which followed the one interrupted; and the step he took was with the left foot, which was the one he would have used if I hadn’t stopped him. I followed him with my eyes. An unusual little boy. A most precisely mechanical little boy.

When he was almost out of sight, I took off after him, wondering.

The house he went into was over in that crumbling section which forms a curving boundary line, marking the limits of those frantic and ugly original mine-workings made many years ago by the early colonists. It seems that someone had told someone who had told someone else that here, a mere twenty feet beneath the surface, was a vein as wide as a house and as long as a fisherman’s alibi, of pure--pure, mind you--gold.

Back in those days, to be a colonist meant to be a rugged individual. And to be a rugged individual meant to not give a damn one way or another. And to not give a damn one way or another meant to make one hell of a mess on the placid face of Mars.

There had not been any gold found, of course, and now, for the most part, the mining shacks so hastily thrown up were only fever scars of a sickness long gone and little remembered. A few of the houses were still occupied, like the one into which the Martian boy had just disappeared.

So his mother had taught him the William Tell Overture, had she? That tickling thought made me chuckle as I stood before the ramshackle building. And then, suddenly, I stopped chuckling and began to think, instead, of something quite astonishing:

How had it been possible for her to teach, and for him to whistle?

All Martians are as tone-deaf as a bucket of lead.

I went up three slab steps and rapped loudly on the weather-beaten door.

The woman who faced me may have been as young as twenty-two, but she didn’t look it. That shocked look, which comes with the first realization that youth has slipped quietly away downstream in the middle of the night, and left nothing but frightening rocks of middle age to show cold and gray in the hard light of dawn, was like the validation stamp of Time itself in her wide, wise eyes. And her voice wasn’t young any more, either.

“Well? And what did I do now?”

“I beg your pardon?” I said.

“You’re Mobile Security, aren’t you? Or is that badge you’re wearing just something to cover a hole in your shirt?”

“Yes, I’m Security, but does it have to mean something?” I asked. “All I did was knock on your door.”

“I heard it.” Her lips were curled slightly at one corner.

I worked up a smile for her and let her see it for a few seconds before I answered: “As a matter of fact, I don’t want to see you at all. I didn’t know you lived here and I don’t know who you are. I’m not even interested in who you are. It’s the little boy who just went in here that I was interested in. The little Martian boy, I mean.”

Her eyes spread as though somebody had put fingers on her lids at the outside corners and then cruelly jerked them apart.

“Come in,” she almost gasped.

I followed her. When I leaned back against the plain door, it closed protestingly. I looked around. It wasn’t much of a room, but then you couldn’t expect much of a room in a little ghost of a place like this. A few knickknacks of the locality stood about on two tables and a shelf, bits of rock with streak-veins of fused corundum; not bad if you like the appearance of squeezed blood.

There were two chairs and a large table intended to match the chairs, and a rough divan kind of thing made of discarded cratings which had probably been hauled here from the International Spaceport, ten miles to the West. In the back wall of the room was a doorway that led dimly to somewhere else in the house. Nowhere did I see the little boy. I looked once again at the woman.

“What about him?” she whispered.

Her eyes were still startled.

I smiled reassuringly. “Nothing, lady, nothing. I’m sorry I upset you. I was just being nosy is all, and that’s the truth of it. You see, the little boy went by me a while ago and he was whistling. He whistles remarkably well. I asked him what the name of the tune was and he told me it was the ‘Calm’ from William Tell. He also told me his mother had taught him.”

Her eyes hadn’t budged from mine, hadn’t flickered. They might have been bright, moist marbles glued above her cheeks.

She said one word only: “Well?”

“Nothing,” I answered. “Except that Martians are supposed to be tone-deaf, aren’t they? It’s something lacking in their sense of hearing. So when I heard this little boy, and saw he was a Martian, and when he told me his mother had taught him--” I shrugged and laughed a little. “Like I said before, I guess I got just plain nosy.”

She nodded. “We agree on that last part.”

Perhaps it was her eyes. Or perhaps it was the tone of her voice. Or perhaps, and more simply, it was her attitude in general. But whatever it was, I suddenly felt that, nosy or not, I was being treated shabbily.

“I would like to speak to the Martian lady,” I said.

“There isn’t any Martian lady.”

“There has to be, doesn’t there?” I said it with little sharp prickers on the words.

But she did, too: “Does there?“

I gawked at her and she stared back. And the stare she gave me was hard and at the same time curiously defiant--as though she would dare me to go on with it. As though she figured I hadn’t the guts.

For a moment, I just blinked stupidly at her, as I had blinked stupidly at the little boy when he told me his mother had taught him how to whistle. And then--after what seemed to me a very long while--I slowly tumbled to what she meant.

Her eyes were telling me that the little Martian boy wasn’t a little Martian boy at all, that he was cross-breed, a little chap who had a Martian father and a human, Earthwoman mother.

It was a startling thought, for there just aren’t any such mixed marriages. Or at least I had thought there weren’t. Physically, spiritually, mentally, or by any other standard you can think of, compared to a human male the Martian isn’t anything you’d want around the house.

I finally said: “So that is why he is able to whistle.”

She didn’t answer. Even before I spoke, her eyes had seen the correct guess which had probably flashed naked and astounded in my own eyes. And then she swallowed with a labored breath that went trembling down inside her.

“There isn’t anything to be ashamed of,” I said gently. “Back on Earth there’s a lot of mixtures, you know. Some people even claim there’s no such thing as a pure race. I don’t know, but I guess we all started somewhere and intermarried plenty since.”

She nodded. Somehow her eyes didn’t look defiant any more.

“Where’s his father?” I asked.

“H-he’s dead.”

“I’m sorry. Are you all right? I mean do you get along okay and everything, now that... ?”

I stopped. I wanted to ask her if she was starving by slow degrees and needed help. Lord knows the careworn look about her didn’t show it was luxurious living she was doing--at least not lately.

“Look,” I said suddenly. “Would you like to go home to Earth? I could fix--”

But that was the wrong approach. Her eyes snapped and her shoulders stiffened angrily and the words that ripped out of her mouth were not coated with honey.

“Get the hell out of here, you fool!”

I blinked again. When the flame in her eyes suddenly seemed to grow even hotter, I turned on my heel and went to the door. I opened it, went out on the top slab step. I turned back to close the door--and looked straight into her eyes.

She was crying, but that didn’t mean exactly what it looked like it might mean. Her right hand had the door edge gripped tightly and she was swinging it with all the strength she possessed. And while I still stared, the door slammed savagely into the casing with a shock that jarred the slab under my feet, and flying splinters from the rotten woodwork stung my flinching cheeks.

I shrugged and turned around and went down the steps. “And that is the way it goes,” I muttered disgustedly to myself. Thinking to be helpful with the firewood problem, you give a woman a nice sharp axe and she immediately puts it to use--on you.

I looked up just in time to avoid running into a spread-legged man who was standing motionless directly in the middle of the sand-path in front of the door. His hands were on his hips and there was something in his eyes which might have been a leer.

“Pulled a howler in there, eh, mate?” he said. He chuckled hoarsely in his throat. “Not being exactly deaf, I heard the tail end of it.” His chuckle was a lewd thing, a thing usually reserved--if it ever was reserved at all--for the mens’ rooms of some of the lower class dives. And then he stopped chuckling and frowned instead and said complainingly:

“Regular little spitfire, ain’t she? I ask you now, wouldn’t you think a gal which had got herself in a little jam, so to speak, would be more reasonable--”

His words chopped short and he almost choked on the final unuttered syllable. His glance had dropped to my badge and the look on his face was one of startled surprise.

“I--” he said.

I cocked a frown of my own at him.

“Well, so long, mate,” he grunted, and spun around and dug his toes in the sand and was away. I stood there staring at his rapidly disappearing form for a few moments and then looked back once more at the house. A tattered cotton curtain was just swinging to in the dirty, sand-blown window. That seemed to mean the woman had been watching. I sighed, shrugged again and went away myself.

When I got back to Security Headquarters, I went to the file and began to rifle through pictures. I didn’t find the woman, but I did find the man.

He was a killer named Harry Smythe.

I took the picture into the Chief’s office and laid it on his desk, waited for him to look down at it and study it for an instant, and then to look back up to me. Which he did.

“So?” he said.

“Wanted, isn’t he?”

He nodded. “But a lot of good that’ll do. He’s holed up somewhere back on Earth.”

“No,” I said. “He’s right here. I just saw him.”

“What?“ He nearly leaped out of his chair.

“I didn’t know who he was at first,” I said. “It wasn’t until I looked in the files--”

He cut me off. His hand darted into his desk drawer and pulled out an Authority Card. He shoved the card at me. He growled: “Kill or capture, I’m not especially fussy which. Just get him!”

I nodded and took the card. As I left the office, I was thinking of something which struck me as somewhat more than odd.

I had idly listened to a little half-breed Martian boy whistling part of the William Tell Overture, and it had led me to a wanted killer named Harry Smythe.

Understandably, Mr. Smythe did not produce himself on a silver platter. I spent the remainder of the afternoon trying to get a lead on him and got nowhere. If he was hiding in any of the places I went to, then he was doing it with mirrors, for on Mars an Authority Card is the big stick than which there is no bigger. Not solely is it a warrant, it is a commandeer of help from anyone to whom it is presented; and wherever I showed it I got respect.

I got instant attention. I got even more: those wraithlike tremblings in the darker corners of saloons, those corners where light never seems quite to penetrate. You don’t look into those. Not if you’re anything more than a ghoul, you don’t.

Not finding him wasn’t especially alarming. What was alarming, though, was not finding the Earthwoman and her little half-breed Martian son when I went back to the tumbledown shack where they lived. It was empty. She had moved fast. She hadn’t even left me a note saying good-by.

That night I went into the Great Northern desert to the Haremheb Reservation, where the Martians still try to act like Martians.

It was Festival night, and when I got there they were doing the dance to the two moons. At times like this you want to leave the Martians alone. With that thought in mind, I pinned my Authority Card to my lapel directly above my badge, and went through the gates.

The huge circle fire was burning and the dance was in progress. Briefly, this can be described as something like the ceremonial dances put on centuries ago by the ancient aborigines of North America. There was one important exception, however. Instead of a central fire, the Martians dig a huge circular trench and fill it with dried roots of the belu tree and set fire to it. Being pitch-like, the gnarled fragments burn for hours. Inside this ring sit the spectators, and in the exact center are the dancers. For music, they use the drums.

The dancers were both men and women and they were as naked as Martians can get, but their dance was a thing of grace and loveliness. For an instant--before anyone observed me--I stood motionless and watched the sinuously undulating movements, and I thought, as I have often thought before, that this is the one thing the Martians can still do beautifully. Which, in a sad sort of way, is a commentary on the way things have gone since the first rocket-blasting ship set down on these purple sands.

I felt the knife dig my spine. Carefully I turned around and pointed my index finger to my badge and card. Bared teeth glittered at me in the flickering light, and then the knife disappeared as quickly as it had come.

“Wahanhk,” I said. “The Chief. Take me to him.”

The Martian turned, went away from the half-light of the circle. He led me some yards off to the north to a swooping-tent. Then he stopped, pointed.

“Wahanhk,” he said.

I watched him slip away.

Wahanhk is an old Martian. I don’t think any Martian before him has ever lived so long--and doubtless none after him will, either. His leathery, almost purple-black skin was rough and had a charred look about it, and up around the eyes were little plaits and folds that had the appearance of being done deliberately by a Martian sand-artist.

“Good evening,” I said, and sat down before him and crossed my legs.

He nodded slowly. His old eyes went to my badge.

From there they went to the Authority Card.

“Power sign of the Earthmen,” he muttered.

“Not necessarily,” I said. “I’m not here for trouble. I know as well as you do that, before tonight is finished, more than half of your men and women will be drunk on illegal whiskey.”

He didn’t reply to that.

“And I don’t give a damn about it,” I added distinctly.

His eyes came deliberately up to mine and stopped there. He said nothing. He waited. Outside, the drums throbbed, slowly at first, then moderated in tempo. It was like the throbbing--or sobbing, if you prefer--of the old, old pumps whose shafts go so tirelessly down into the planet for such pitifully thin streams of water.

“I’m looking for an Earthwoman,” I said. “This particular Earthwoman took a Martian for a husband.”

“That is impossible,” he grunted bitterly.

“I would have said so, too,” I agreed. “Until this afternoon, that is.”