Choose any of the above.

This story was solicited by Playboy as part of a projectwherein they intended to obtain a dozen short sciencefiction pieces from a dozen different science fiction writers and then run one a month for a year with lavishillustrations by the French artist Philippe DruilleL Iattempted here to do something which would give himlots of scope for his art. Playboy changed its mind,though, dropped the project and paid me my kill-fee.I've occasionally wondered what the illustrations wouldhave been like.

They drifted toward the Earth, took up stations at itsTrojan points.

They regarded the world, its two and a half billionpeople, their cities, their devices.

After a time, the inhabitant of the forward point spoke:

"I am satisfied."

There was a long pause, then, "It will do," said theother, fetching up some strontium-90.

Their awarenesses met above the metal.

"Go ahead," said the one who had brought it.

The other insulated it from Time, provided antipodalpathways, addressed the inhabitant of the trailing point:

"Select."

"That one."

The other released the stasis. Simultaneously, they became aware that the first radioactive decay particle emitted fled by way of the opposing path.

"I acknowledge the loss. Choose."

"I am Dust," said the inhabitant of the forward point."Three moves apiece."

"And I am Blood," answered the other. "Three moves.Acknowledged."

"I choose to go first."

"I follow you- Acknowledged."

They removed themselves from the temporal sequence; and regarded the history of the world.

Then Dust dropped into the Paleolithic and raised anduncovered metal deposits across the south of Europe.

"Move one completed."

Blood considered for a timeless time then moved tothe second century B.C. and induced extensive lesions inthe carotids of Marcus Porcius Cato where he stood inthe Roman Senate, moments away from another "Carthago delenda est."

"Move one completed."

Dust entered the fourth century A.D. and injected anair bubble into the bloodstream of the sleeping JuliusAmbrosius, the Lion of Mithra.

"Move two completed."

Blood moved to eighth-century Damascus and did thesame to Abou Iskafar, in the room where he carved curling alphabets from small, hard blocks of wood,

"Move two completed."

Dust contemplated the play.

"Subtle move, that."

**Thank you."

"But not good enough, I feel. Observe."

Dust moved to seventeenth-century England and, onthe morning before the search, removed from his laboratory all traces of the forbidden chemical experimentswhich had cost Isaac Newton his life.

"Move three completed."

"Good move. But I think I've got you."

Blood dropped to early nineteenth-century Englandand disposed of Charles Babbage.

"Move three completed."

Both rested, studying the positions.

"Ready?" said Blood.

"Yes."

They reentered the sequence of temporality at thepoint they had departed.

It took but an instant. It moved like the cracking of awhip below them. ...

They departed the sequence once more, to study theseparate effects of their moves now that the general resultwas known. They observed; The south of Europe flourished. Rome was foundedand grew in power several centuries sooner than had previously been the case. Greece was conquered before theflame of Athens burned with its greatest intensity. Withthe death of Cato the Elder the final Punic Warwas postponed. Carthage also continued to grow, extending her empire far to the east and the south. The deathof Julius Ambrosius aborted the Mithraist revival andChristianity became the state religion in Rome. TheCarthaginians spread their power throughout the middleeast Mithraism was acknowledged as their state religion.The clash did not occur until the fifth century. Carthageitself was destroyed, the westward limits of its empirepushed back to Alexandria. Fifty years later, the Popecalled for a crusade. These occurred with some regularityfor the next century and a quarter, further fragmentingthe Carthaginian empire while sapping the enormousbureaucracy which had grown up in Italy. The fightingfell off, ceased, the lines were drawn, an economic, depression swept the Mediterranean area. Outlying districts grumbled over taxes and conscription, revolted.The general anarchy which followed the war of secession settled down into a dark age reminiscent of that inthe initial undisturbed sequence. Off in Asia Minor, theprinting press was not developed.

"Stalemate till then, anyway," said Blood.

"Yes, but look what Newton did."

"How could you have known?"

"That is the difference between a good player and aninspired player. I saw his potential even when he wasfooling around with alchemy. Look what he did for theirscience, single-handed—everything! Your next move wastoo late and too weak."

"Yes. I thought I might still kill their computers bydestroying the founder of International Difference Machines, Ltd."

Dust chuckled.

"That was indeed ironic. Instead of an IDM 120, theBeagle took along a young naturalist named Darwin."

Blood glanced along to the end of the sequence wherethe radioactive dust was scattered across a lifeless globe.

"But it was not the science that did it, or the religion."

"Of course not," said Dust. "It is all a matter of emphasis."

"You were lucky. I want a rematch."

"All right. I will even give you your choice: Blood orDust?"

"I'll stick with Blood."

"Very well. Winner elects to go first Excuse me."

Dust moved to second century Rome and healed thecarotid lesions which bad produced Cato's cerebral hemorrhage."Move one completed."

Blood entered eastern Germany in the sixteenth century and induced identical lesions in the Vatican assassinwho had slain Martin Luther.

"Move one completed."

"You are skipping pretty far along."

"It is all a matter of emphasis."

"Truer and truer. Very well. You saved Luther. I willsave Babbage. Excuse me."

An instantless instant later Dust had returned.

"Move two completed."

Blood studied the playing area with extreme concentration. Then, "AU right."

Blood entered Chewy's Theater on the evening in1865 when the disgruntled actor had taken a shot atthe President of the United States. Delicately altering thecourse of the bullet in midair, he made it reach its target

"Move two completed."

"I believe that you are bluffing," said Dust "Youcould not have worked out all the ramifications."

"Wait and see."

Dust regarded the area with intense scrutiny.

"All right, then. You killed a president. I am going tosave one—or at least prolong his life somewhat. I wantWoodrow Wilson to see that combine of nations founded.Its failure will mean more than if it had never been—andit will faiL —Excuse me."

Dust entered the twentieth century and did some repair work within the long-jawed man.

"Move three completed."

"Then I, too, shall save one."

Blood entered the century at a farther point and assured the failure of Leon Nozdrev, the man who had assassinated Nikita Khrushchev.

"Move three completed."

"Ready, then?"

"Ready."

They reentered the sequence. The long whip cracked.Radio noises hummed about them. Satellites orbitted theworld. Highways webbed the continents. Dusty citiesheld their points of power throughout. Ships clove theseas. Jets slid through the atmosphere. Grass grew. Birdsmigrated. Fishes nibbled.

Blood chuckled."You have to admit it was very close," said Dust.

"As you were saying, there is a difference between agood player and an inspired player."