Thuck - Thuck - Thuck - the executioner's sword flamed in sunlight and descended. The heads fell into a ditch and were immediately covered over with loose black earth. The next Mong, who had been waiting patiently, squatting with his hands bound behind him, spat in contempt and moved, into place at the edge of the ditch. Thuck - the head rolled down to join the others, the mouth still contorted in a grimace of defiance.

These Mongs died well, Blade thought as he watched from a high tower on the great wall. He waited for Lali to join him. They then would mount horses and ride along the top of the wall to inspect the Cath forces and survey the Mong camp out on the plain where the black sand never stopped swirling. Blade had now been three weeks in Cath. Already he was restless, and dared not show it.

Queko, Chief Captain of the Caths under the Empress Mei, stood beside Blade on the tower. As tall as Blade, but very slim, he had the lemon-colored skin and the handsome straight features that distinguished the Caths. A fine soft fuzz covered his upper lip and chin. Caths had very little facial hair.

Blade, on the other hand, had by this time a luxuriant black beard which he kept trimmed short.

Blade had voiced his thought aloud. Queko, who so far had shown neither hostility nor friendliness to Blade, said: "They are savages. Barbarians. They have no imagination and therefore they have no fear. Why shouldn't they die well? They have been taught that they will prevail in the end, so one Mong more or less does not matter. They may be right. There are millions of Mongs. The more we kill the more they come."

Queko spoke in the high-pitched musical tones of the Caths. His eyes glittered sideways at Blade.'"Perhaps, Sir Blade, you have by now found a solution to this problem. I hope so, because the Mongs are bleeding us like leeches."

Blade concealed a smile. J and Lord L would be a little surprised to know that he had promoted himself to a Sir. But it had been necessary. Back in H-Dimension it meant little, here in Cath it was most important.

He said nothing more. Queko excused himself on plea of military affairs and left him. Blade watched the long lines of captive Mongs, squatting patiently on the plain behind the city, move toward the executioner. Something of a paradox here. The Mongs took no captives. The Caths took them, treated them well, then cut off their heads.

Blade turned away. He was beginning to feel uneasy. He was also aware that he was not doing his job very well. He was in X-Dimension to explore, investigate, probe. Yet he had been three weeks in the same place.

The fact was that he was as much a captive as any of the Mongs.

He descended the tower and stood on the broad roadway atop the wall. Here came his captor now. Lali. She who bound him with chains of silk and flesh.

She came riding toward him, sitting well in the high wooden saddle. She wore a little peaked cap atop high piled hair, a small corselet of painted wood, and flowing breeches stuffed into tiny boots. Underneath she would be wearing the diaphanous body sheath with which he was now so familiar.

Lali pulled her horse up and saluted him with her whip. "Good morning, Sir Blade."

"Good morning, Lali." They exchanged a secret smile. The Sir was Blade's sole contribution to the tremendous lie they were living.

A horse was brought for Blade and he swung easily into the saddle. "Come, Lali, let's ride down to the cannon."

They rode together down the wall, past groups of Cath soldiery and officers preparing for the day's fighting. Hearts were touched with fingertips as Lali rode by, and the brawny, bearded Blade was the object of curious stares. It was the same day after day. They did not understand Blade, nor did they question. Lali was an absolute ruler - compared to her Catherine the Great had been a democrat - and if their Empress wanted Blade, who was to question it?

Lali touched his knee with her whip. "You left me early this morning, Sir Blade. I awoke to an empty bed. I do not like that." The deep green eyes were narrowed on him.

Blade did not apologize. He knew better, and in any case apology was foreign to his nature.

"I had business," he said brusquely. "I made an early tour of inspection. I am trying to think of a plan to rid us of these Mongs, Lali. I cannot do it in bed."

Lali expected love-making every morning before rising. She explained it in direct speech. "Mei Saka, may he rot in the bellies of the carrion apes, had not touched me for two years before you came, Blade. I am a woman of great passion and demand."

They came now to the great cannon and dismounted. "I will forgive you this time," she said. "Not again."

The silken leash.

Blade inspected the huge gun with his usual awe and amusement. Lali could never understand why he was so fascinated by it. It had always been there, ever since she was a child, and the explosions frightened her almost as much as they did the Mongs.

She watched, a trifle impatiently, as Blade walked around the cannon. He had been very nearly right in his first estimates. The muzzle was five feet across, not six, but the gun was sixty feet long. The wheels of its eight-wheeled carriage were twelve feet high. It took ten barrels of crude powder to charge it and five hundred men to move it up and down the ramp. What puzzled Blade was why the damned thing had never blown up. The barrel was of wood, thick and ornately carven, and reinforced with wide steel rings. Steel was hard to come by in this province of Cath. It all had to come from the south, from the Imperial City of Pukka.

Blade shrugged, as he always did, and went back to Lali. Those old gunsmiths must have known something about wood, something that had been lost with the years.

Together they watched the Mongs moving about out on the plain. The sturdy little horses, long haired and with bushy manes and tails, wheeled and swooped amid the blowing clouds of Hack sand. Soon the attacks would begin. Day after day.

Year after year, as Lali explained later that night.

"Khad Tambur, the Lord of the Mongs, wants the big gun. If we let him have it he will make peace and go away."

They had been in Lali's bed. Blade, yawning, said: "Then why not give him the gun? What use is it? You never kill any Mongs with it - you just scare them and then they come right back."

For the first time he saw her horrified - and angry. The lovely eyes darted green sparks at him.

"Give them the gun? Give Khad Tambur our gun! You are mad, Blade. No! Not mad. I forget you are a stranger. But the gun is the symbol of Cath. There is a legend. When the gun is captured Cath is doomed. He who possesses the cannon rules the world. That is why Khad Tambur is so determined to have it. For the power it brings. Why he keeps trying year after year, and why he sacrifices so many hundreds of thousands of his men. Give up the gun! Never breathe that again, Blade. Even I could not save you. The people would tear you apart."

Blade had pressed her back on the bed and forgotten it.

This morning there was a sense of something different in the air. The Mongs did not attack as usual. There was the usual scurry and bustle in the great, village of black tents and the cooking fire smoke hung in clouds above the plain and mingled with the blowing black sand. But the usual forays did not come. The milling horsemen stayed out of range, making no effort to entice the defenders out for a battle, and the foot soldiers did not come forward with their scaling ladders.

Blade wondered if the Khad Tambur had suddenly found wisdom? Until now he had been a singularly obtuse commander, wasting men against the wall day after day.

Lali, shielding her eyes with a hand, stared over at the Mong camp. She wrinkled her beautiful nose. "Something is wrong, Sir Blade. They do not come to fight as usual."

Blade smiled. "Maybe the Khad is getting smart at last. He is going to fold his tents and steal away. I know I would have, long ago. He can't win this way."

Lali chewed her lip with small perfect teeth. "That is not good, Sir Blade. We must kill Mongs. Every day we must kill more and more Mongs. How can we do that if they go away?"

Blade pointed. "Look! Maybe your answer is coming now. He's not very big, is he?"

A single horseman had left the Mong camp and was riding toward the wall. As he drew near Blade could not repress a smile. The rider was a dwarf, or midget, dressed as a Mong warrior. Over his head, on a small lance, he waved a single horse tail.

Blade looked at the girl. "He wants a parley. But why send a dwarf, a stunted man? He can't really be a warrior."

Her face was pale, the emerald eyes blazing with rage. "It is Khad Tambur's idea of a joke. An insulting joke. No - it must be the idea of that bitch whore! Sadda, Khad's sister. It is like her to think of an insult like this."

The little man, riding a little pony, stopped near a postern in the great wall. He waved his horse tail all the while he shouted in a voice that was amazingly gruff and deep. The Cath soldiers, obedient to orders, did not fire. Blade quickly mounted and rode up the wall road until he was directly over the tiny rider. Queko was there, a tolerant smile on his handsome face, along with a little group of Cath officers.

The little warrior was sturdily built in perfect proportion. Off the pony, Blade judged, the man would be less than three feet tall. Yet his legs were heavily muscled and his biceps bulged.

The Mongs used no stirrups. The messenger sprang lightly to stand on the saddle, perfectly balanced, and cupped his hands as he shouted up at the towering wall.

"Caths! Soldiers of the province of Serendip, of the land of Cath, and most especially to the Empress Mei and all her high officers - the Khad Tambur sends you this offer. Listen well, for it is Khad Tambur who speaks through me, Khad Tambur who is the Scourge of the World and Shaker of the Universe."

One of the common soldiers laughed and shouted back. "Get on with it, minikin. Stop blowing through your mouth and say what you have come to say! Then go before we put a little arrow through your little carcass."

A Cath officer struck the man and he fell back, muttering.

The messenger shouted on: "The great Khad Tambur has many ears within your wall..."

Lali, who had come spurring up to join Blade, scowled and said, "That is true enough! Spies."

Blade winked at her and patted her knee. "Be quiet, Lali. Please. I want to hear what the rascal has to say."