"Wait," Fred said. He had caught it, the familiar, pleasing stench. It came from a booth on his right and he turned at once in that direction.

A plump, gray-colored middle-aged woman stood in a ringtoss booth, her hands full of the light wicker rings.

Behind Fred his father said to Hoagland Rae, "You get the rings over the merchandise; you win whatever you manage to toss the ring onto so that it stays." With Fred he walked slowly in that direction. "It would be a natural," he murmured, "for a psychokinetic. I would think."

"I suggest," Hoagland said, speaking to Fred, "that you look more closely this time at the prizes. At the merchandise." However, he came along, too.

At first Fred could not make out what the neat stacks were, each of them exactly alike, intricate and metallic; he came up to the edge of the booth and the middle-aged woman began her chant-like litany, offering him a handful of rings. For a dollar, or whatever of equal value the settlement had to offer.

"What are they?" Hoagland said, peering. "I – think they're some kind of machines."

Fred said, "I know what they are." And we've got to play, he realized. We must round up every item in the settlement that we can possibly trade these people, every cabbage and rooster and sheep and wool blanket.

Because, he realized, this is our chance. Whether General Wolff knows about it or likes it.

"My God," Hoagland said quietly. "Those are traps."

"That's right, mister," the middle-aged woman chanted. "Homeostatic traps; they do all the work, think for themselves, you just let them go and they travel and travel and they never give up until they catch -" She winked. "You know what. Yes, you know what they catch, mister, those little pesky things you can't ever possibly catch by yourselves, that are poisoning your water and killing your steers and ruining your settlement – win a trap, a valuable, useful trap, and you'll see, you'll see!" She tossed a wicker ring and it nearly settled over one of the complex, sleek-metal traps; it might very well have, if she had thrown it just a little more carefully. At least that was the impression given. They all felt this.

Hoagland said to Tony Costner and Bob Turk, "We'll need a couple hundred of them at least."

"And for that," Tony said, "we'll have to hock everything we own. But it's worth it; at least we won't be completely wiped out." His eyes gleamed "Let's get started " To Fred he said, "Can you play this game? Can you win?"

"I think so," Fred said. Although somewhere nearby, someone in the carnival was ready with a contrary power of psychokinesis. But not enough he decided. Not quite enough.

It was almost as if they worked it that way on purpose.

Not by its Cover

The elderly, cross-tempered president of Obelisk Books said irritably, "I don't want to see him, Miss Handy. The item is already in print; if there's an error in the text we can't do anything about it now."

"But Mr. Masters," Miss Handy said, "it's such an important error, sir. If he's right. Mr. Brandice claims that the entire chapter -"

"I read his letter; I also talked to him on the vidphone. I know what he claims." Masters walked to the window of his office, gazed moodily out at the arid, crater-marred surface of Mars which he had witnessed so many decades. Five thousand copies printed and bound, he thought. And of that, half in gold-stamped Martian wub-fur. The most elegant, expensive material we could locate. We were already losing money on the edition, and now this.

On his desk lay a copy of the book. Lucretius' De Rerum Natura, in the lofty, noble John Dryden translation. Angrily, Barney Masters turned the crisp white pages. Who would expect anyone on Mars to know such an ancient text that well? he reflected. And the man waiting in the outer office consisted of only one out of eight who had written or called Obelisk Books about a disputed passage.

Disputed? There was no contest; the eight local Latin scholars were right. It was simply a question of getting them to depart quietly, to forget they had ever read through the Obelisk edition and found the fumbled-up passage in question.

Touching the button of his desk intercom, Masters said to his receptionist, "Okay; send him." Otherwise the man would never leave; his type would stay parked outside. Scholars were generally like that; they seemed to have infinite patience.

The door opened and a tall gray-haired man, wearing old-fashioned Terra-style glasses, loomed, briefcase in hand. "Thank you, Mr. Masters," he said, entering. "Let me explain, sir, why my organization considers an error such as this so important." He seated himself by the desk, unzipped his briefcase briskly. "We are after all a colony planet. All our values, mores, artifacts and customs come to us from Terra. WODAFAG considers your printing of this book…"

" 'WODAFAG'?" Masters interrupted. He had never heard of it, but even so he groaned. Obviously one of the many vigilant crank outfits who scanned everything printed, either emanating locally here on Mars or arriving from Terra.

"Watchmen Over Distortion And Forged Artifacts Generally," Brandice explained. "I have with me an authentic, correct Terran edition of De Rerum Natura - the Dryden translation, as is your local edition." His emphasis on local made it sound slimy and second-rate; as if, Masters brooded, Obelisk Books was doing something unsavory in printing books at all. "Let us consider the inauthentic interpolations. You are urged to study first my copy -" He laid a battered, elderly, Terran-printed book open on Masters' desk. "- in which it appears correctly. And then, sir, a copy of your own edition; the same passage." Beside the little ancient blue book he laid one of the handsome large wub-fur bound copies which Obelisk Books had turned out.

"Let me get my copy editor in here," Masters said. Pressing the intercom button he said to Miss Handy, "Ask Jack Snead to step in here, please."

"Yes, Mr. Masters."

"To quote from the authentic edition," Brandice said, "we obtain a metric rendering of the Latin as follows. Ahem." He cleared his throat self-consciously, then began to read aloud.

"From sense of grief and pain we shall be free;

We shall not feel, because we shall not be.

Though earth in seas, and seas in heaven were lost,

We should not move, we only should be toss'd."

"I know the passage," Masters said sharply, feeling needled; the man was lecturing him as if he were a child.

"This quatrain," Brandice said, "is absent from your edition, and the following spurious quatrain – of God knows what origin – appears in its place. Allow me." Taking the sumptuous, wub-fur bound Obelisk copy, he thumbed through, found the place; then read.

"From sense of grief and pain we shall be free;

Which earth-bound man can neither qualify nor see.

Once dead, we fathom seas cast up from this:

Our stint on earth doth herald an unstopping bliss."

Glaring at Masters, Brandice closed the wub-fur bound copy noisily. "What is most annoying," Brandice said, "is that this quatrain preaches a message diametric to that of the entire book. Where did it come from? Somebody had to write it; Dryden didn't write it – Lucretius didn't." He eyed Masters as if he thought Masters personally had done it.

The office door opened and the firm's copy editor, Jack Snead, entered. "He's right," he said resignedly to his employer. "And it's only one alteration in the text out of thirty or so; I've been ploughing through the whole thing, since the letters started arriving. And now I'm starting in on other recent catalog-items in our fall list." He added, grunting. "I've found alterations in several of them, too."