But this did not seem to me a mirage sort of experience. I rubbed my eyes. I changed the position of my head. I closed and opened my eyes.

“No,” I said. “I see an oasis clearly.”

“It is not there,” said Hassan.

“Does the oasis of the Battle of Red Rock have, at its northeast rim, a kasbah, with four towers?”

“Yes,” said Hassan.

“Then I see it,” I said.

“No,” said Hassan.

“There are palm groves, five of them,” I said.

“Yes.” he said.

“Pomegranate orchards lie at the east of the oasis.” I said. “Gardens lie inward. There is even a pond, between two of the groves of date palms.”

“True,” said Hassan.

“There is Red Rock,” I said.

“No.” said Hassan.

“I could not imagine these things,” I said. “I have never been to Red Rock.

Look. There is a single gate in the kasbah, facing us. On the towers two flags fly.”

Petitions,” said Hassan, “of the Tashid and Aretai.”

“I shall race you to the oasis,” I said.

“It is not there,” he said. “We shall not arrive there until tomorrow, past noon.”

“I see it!” I protested.

“I shall speak clearly,” said Hassan. “You see it and you do not see it.”

“I am glad,” I said, “that you have chosen to speak clearly. Had you spoken obscurely I might not have understood.”

“Ride ahead,” suggested Hassan.

I shrugged, and kicked the kaiila in the flanks, urging downward, from the sloping hill, toward the oasis. I had ridden for no more than five Ehn when the oasis vanished. I reined in the kaiila. Before me was nothing but the desert.

I was sweating. I was hot. Before me was nothing but the desert.

“It is an interesting phenomenon, is it not?” asked Hassan, when he, and the others, had joined me. “The oasis, which is some seventy pasangs distant, is reflected in the mirror of air above it, and then again reflected downward and away, at an angle.”

“It is like mirrors?” I asked.

“Precisely,” said Hassan, “with layers of air the glass. A triangle of reflected light is formed. Red Rock, more than seventy pasangs away, is seen, in its image, here.”

“It is only then an optical illusion?’’ I asked.

“Yes,” said Hassan.

“But did it not seem real to you?” I asked.

“Of course,” he said.

“How did you know it was not Red Rock?” I asked.

“I am of the Tahari,” he said.

“Did it look different to you?” I asked.

“No,” he said.

“Then how could you tell?” I asked.

He shrugged. “I am of the Tahari,” he said.

“But how could you tell?” I asked.

“By distances and times,” he said. “We had not come far enough, nor at our pace, fast enough, for it to be Red Rock.”

“Seeing it,” I said, “one who was unwise, and not of the Tahari, might ration water unwisely, and die.”

“In the Tahari,” said Hassan, “it is well to be of the Tahari, if one would live.”

“I will try to be of the Tahari,” I said.

“I will help you,” said Hassan.

It was the next day, at the eleventh Ahn, one Ahn past the Gorean noon, that we arrived at the Oasis of Red Rock.

It was dominated by the kasbah of its pasha, Turem a’Din, commander of the local Tashid clans, on its rim to the northeast. There were five palm groves. At the east of the oasis lay pomegranate orchards. Toward its lower parts, in its center, were the gardens. Between two of the groves of date palms there was a large pool. The kasbah contained a single gate. On the summits of its four towers flew petitions, those of the Tashid and Aretai.

“Do you fear to enter the oasis of a vassal tribe of the Aretai?” asked Hassan.

“We are far from Nine Wells,” I said.

“I think, too, there is little danger,” said Hassan.

We entered the oasis slowly, single file, in caravan style. There is almost always a constant, hot wind on the Tahari. Our burnooses lifted behind us, slowly, swelling, over the flanks of our animals. The girl, Alyena rode next to the last in our line, in the position of least status; she was followed by one of Hassan’s men, the guard; such a guard is commonly posted; he, from time to time, watches the trail behind the caravan and, of course, prevents the escape of slave girls.

The oasis, which we were entering, is named for the Battle of Red Rock, which is a large shelf of reddish sandstone behind the oasis, north by northeast from its lowest point, and center. It was used as the vantage point for the Aretai commander at that time, Hammaran, who also launched at a crucial point in the struggle, his picked cavalry, and bodyguard, from that height, turning the battle’s tide. The Tashid commander of the time, Ba’Arub, died on the shelf of red stone, with ten men, trying to reach Hammaran. It was said that he came within ten yards of him. Ba’Arub was, it was said, a brave man. It was also believed that if he had stood siege in his kasbah, in time Hammaran would have been forced to retire. It is difficult to maintain a lengthy siege in the Tahari. Food supplies at the oasis are short, except for the stores in the kasbah, and supply lines are long, and difficult to defend. Had Ba’Arub destroyed or fouled the public wells at Red Rock, those outside the walls of the kasbah, Hammaran would have been forced to retire in twenty-four hours, and perhaps lose most of his men on the return march to his country. But, being of the Tahari, Ba’Arub, as it is told in the stories, related about the campfires, would not do this. It is said he came within ten yards of Hammaran.

Men regarded us with some curiosity, as is common when newcomers arrive at an oasis, but I detected neither apprehension nor hostility. The wars and raids, I gathered, had not touched Red Rock.

A child ran beside the stirrup of Hassan, playing. “You have no bells on your kaiila,” said the child.

“They were stolen by raiders,” said Hassan. The boy laughed and ran beside him.

“We shall seek an inn,” said Hassan.

The battle of Red Rock, for which the oasis is named, took place more than seventy years ago, in 10,051 C.A., or in the sixth year of the reign of Ba’Arub Pasha. Since that time the Tashid have been a vassal tribe of the Aretai. Though there are some token tributes involved, exemptions for Aretai merchants from caravan taxes, and such, the vassal tribe is, in its own areas, almost completely autonomous, with its own leaders, magistrates, judges and soldiers.

The significance of the relationship is, crucially, interestingly, military alliance. The vassal tribe is bound, by its Tahari oaths, sworn over water and salt, to support the conquering tribe in its military endeavors, with supplies, kaiila and men. The vassal tribe is, in effect, a military unit subordinate to the conquering tribe which it, then, may count among its forces. Enemies conquered become allies enlisted. One’s foe of yesterday becomes one’s pledged friend of today. The man of the Tahari, conquered, stands ready, his scimitar returned to him, to defend his conqueror to the death. The conqueror, by his might and cunning, and victory, has won, by the right of the Tahari, a soldier to his cause. I am not clear on the historical roots of this unusual social institution but it does tend, in its practice, to pacify great sections of the Tahari. War, for example, between conquering tribes and rebellious vassal tribes is, although not unknown, quite rare, Another result, perhaps unfortunate, however, is that the various tribes tend to build into larger and larger confederations of militarily related communities. Thus, if war should erupt between the high tribes, the conquering tribes, the entire desert might become engulfed in hostilities. This was what was in danger of happening now, for the Aretai and the Kavars were the two high tribes of the Tahari. Not all tribes, of course, are vassal or conquering tribes. Some are independent. War, incidentally, between vassal tribes is not unknown. The high tribes need not, though often they do, support vassal tribes in their squabbles; the vassal tribes, however, are expected to support the high, or noble, tribes, in their altercations. Sometimes, it is made quite clear, by messenger and proclamation, whether a war is local or not, say, between only the Ta’Kara and the Luraz, who have some point of dispute between them. All in all, the relation of vassal tribe to conquering tribe probably contributes more to the peace of the Tahari than to its hostilities. It is fortunate that some such arrangement exists for the men of the Tahari, like Goreans generally, are extremely proud, high-strung, easily offended men, with a sense of honor that is highly touchy. Furthermore, enjoying war, they need very little to send them to their saddles with their scimitars loose in their sheaths. A rumor of an insult or outrage, not inquired closely into, perhaps by intent, will suffice, A good fight, I have heard men of the Tahari say, licking their lips, justifies any cause. It may be appropriate here to mention that the reason that Hammaran came to Red Rock seventy years ago is not even known, by either Aretai or Tashid. The cause of the war was forgotten, but its deeds are still recounted about the fires. There were seventy men in the bodyguard of Hammaran. When the battle was lost to him, Ba’Arub tried to reach him. It is said he came within ten yards.