Throughout the greater part of the morning the pursuit continued without the sampan gaining upon the larger boat. Indeed, when they had sailed a few miles towards the east it became apparent to Ling that they were losing ground, that the distance between the two boats was gradually becoming greater.

The man was infuriated. He stood at his great height in the bows of the sampan from time to time, shaking his fist at the scarlet coat of Men-Ching, who was plainly visible upon the deck of the river-junk. After a time, however, Ling's wrath subsided; and seating himself, he confined his attention to the management of the sail. Frank, who was in the stern of the boat, had received orders to steer.

Ling shrugged his great shoulders and came out with a kind of grunt.

"He shall not escape me," said he, talking aloud to himself. "The old fool would be wiser to haul down the sail of the wupan and throw himself upon my mercy."

Frank, summoning to his aid all his moral courage, decided to question the man outright, taking the bull by the horns.

"Why do you want this man Men-Ching?" he asked.

Ling looked up, lifting his black eyebrows, and then chuckled.

"Men-Ching carries upon his person certain letters," said he. "I would have you to know that those letters are worth thousands of dollars."

Frank Armitage was so much astonished that it was some moments before he could recover his presence of mind. How was this man, of all people, in possession of such information? Ling was certainly not a member of Cheong-Chau's brigand band. It was only a week before that Men-Ching had been entrusted with the letters--indeed, he had not been given possession of them until immediately after they were written. The whole thing was a mystery that Frank was in no position to solve.

Sitting amidships in the boat, the man continued to chuckle.

"I will find him in Canton," said he. "He is certain to go to the house of Ah Wu. There I will find him. I will take possession of those letters. A score of men could not prevent me. If Men-Ching hands them over quietly all will be well. If he resists, I cannot say what will happen." And Ling shrugged his shoulders.

Frank was dismayed. It took him some time to realise the extreme gravity of the situation. There was something in the aspect of the boisterous Honanese giant, seated immediately before him, that made the boy feel quite sure that Ling seldom failed in any enterprise he undertook. The man was at once clever, strong and unscrupulous. He meant to obtain those letters, and Frank felt quite sure that he would not fail to do so.

That brought the boy face to face with the fact that the lives of his uncle and Mr Waldron were in the greatest danger. Ling no doubt intended to appropriate the ransom, thus foiling Cheong-Chau. In these circumstances, there could be but little doubt that the brigand chief, robbed of what he already regarded as his own property, would put both his captives to death out of sheer fiendish spite.

Frank could not for the life of him think what course he should take. His brain was in a whirl. In the end he decided that at any cost he must escape from Ling the moment they arrived at Canton, where he hoped to gain an interview with the British consul.

Throughout the remainder of the journey the boy's thoughts ran continuously upon the mystery in which he found himself enveloped. He could not explain it, and after a time he gave up attempting to do so. He neither knew who Ling was nor how the man had such intimate knowledge of Cheong-Chau's affairs. He regretted bitterly that he had rendered Ling such valuable assistance. He was, however, determined never to do so again, and during the pursuit down the river he even went so far as to hold the sampan back by means of the oar with which he was supposed to be steering. All the time he was doing so his heart was beating rapidly, since he dared not think what would happen to him if Ling discovered his deception.

When they reached the great city of Canton it was still early in the morning. Ling hauled down the sail and himself took charge of the stern oar, by means of which he propelled the boat into the narrow creek that separates the main part of the city from the island of Shamien. Running into the bank alongside a sea-going junk, he ordered Frank to step ashore. The boy did so, determined to avail himself of his first chance to escape. In such narrow, close-packed streets as those of the great southern city, he thought he would have many opportunities of giving Ling the slip. He did not expect any difficulty in getting away, since he had no reason to believe that Ling required his services any longer.

Frank--as the saying goes--had counted his chickens before they were hatched. They had not progressed thirty yards along one of the main streets of the city before Frank dived down a side street, brushed past a party of coolies, and then turned into a still smaller street to the right. There he found a ricksha. Jumping into this, he ordered the ricksha coolie to go ahead as fast as he could. The man had picked up the shafts, and was about to set forward, when Frank was seized by the scruff of the neck and lifted bodily from the seat. He was then thrown so violently to the ground that one of his knees was cut and his elbows badly bruised.

Gathering himself together, he looked up, and found himself at the feet of Ling.

"Do you take me for a fool?" roared the man. "Why have you run away?"

"I did not think," answered the boy, somewhat weakly, "that you needed me any longer."

"No more I do," said Ling. "But you know too much about me. When I have run Men-Ching to ground, and emptied the old rascal's pockets, then you are free to go where you like. For the present you remain with me."

He bent down, and seizing the boy by a wrist, dragged him to his feet. Then he set off walking briskly through the narrow streets, dragging the boy after him like a dog on a leash and roughly thrusting aside everyone who got in his way.

In about ten minutes they found themselves in the neighbourhood of the Mohammedan Mosque. Having crossed the main street that runs parallel to the river, Ling turned into a by-street, and thence into the blind alley, at the termination of which was Ah Wu's opium den.

He kicked open the door with his foot and thrust the boy inside. Frank found himself standing before the embroidered curtains that were suspended across the entrance of the smoking-room. Ling lifted his great voice in a kind of shout, mingling his words with triumphant laughter.

"Ah Wu," he cried, "give welcome to a visitor who loves you. There is one here whom it will rejoice your heart to see. Come forth, old fox, and greet the mighty Ling!"

Having delivered himself thus dramatically, he flung the curtains aside, and stepped into the opium den, dragging Frank with him.

Ah Wu, as fat and crafty-looking as ever, stood in the centre of the lower room in front of the stairs that led to the balcony above.

He was holding in his hand a blue china bowl filled with samshu. And so dismayed was he when he set eyes upon his gigantic guest that the bowl fell from his hand and smashed to atoms on the floor.

"Ling!" he gasped.

"The same," roared Ling. "And this time I come not to debate and argue, to exchange words with liars. I come for Men-Ching. I have reason to believe that he is here."

Ah Wu strove to pretend he was delighted to welcome Ling. He smiled from ear to ear, his little eyes almost disappearing in the fat of his face. He bowed, folding his hands in the prescribed Chinese fashion. He even took a few steps forward, so that he was almost within reach of the long arms of the Honanese.

"Men-Ching," said he, still smiling, "is not here."

And no sooner had the words left his lips than he was given a practical and somewhat painful demonstration of the violent character of the man with whom he had to deal. Upon the right of the entrance, adorned by the embroidered curtains, was a lacquer table, upon which stood a heavy china vase. Without a word of warning, Ling seized this vase by the neck, and hurled it with all his force at the proprietor of the opium den. The ornament must have weighed several pounds, and it struck Ah Wu fair in the chest, with the result that he went over backwards and lay, stretched at his full length, at the foot of the staircase. Almost a minute elapsed before he struggled to his feet. Ling had not moved.

"And now," he roared, "lie to me again."

In the meantime, in spite of such extraordinary happenings, Frank had taken in his surroundings. Ah Wu's opium den has been already described--except that we saw it before at night, when the place was crowded. On this occasion there was only one man asleep upon a couch in the lower room. It was about twelve o'clock in the morning, and at this hour, as a general rule, Chinese opium dens are empty, the smokers of the previous evening having departed and the day's customers not having arrived.

Strangely enough, the vase had not broken, but in falling to the floor it had made a considerable noise, and this was sufficient to awaken the sleeper, who evidently suffered from a guilty conscience. The man sprang to his feet, and rushed to the entrance, as if he intended to escape. There, of course, he found his way barred by Ling, who lifted one of his huge fists as if to strike the fellow. The man jumped backward like a cat that finds itself face to face with a dog. And it was then, once again, that Ling burst into one of his boisterous fits of laughter.

"And here's the flunkey!" he cried. "Here's the Hong-Kong cur-dog! Have you also a mind to lie to me, or do you set a value on your life? I tell you truly, I am not here to exchange words. I know what I want, and I am come to get it. Hands up!" he shouted, seeing the man move one of his hands to his waistbelt, under his coat, where he might have carried a firearm. "Hands up, or I wring your neck like a duck!"

In fear and trembling the man lifted both hands above his head. Frank regarded him then for the first time. And it was as if the boy's heart had suddenly ceased to beat when he recognised Yung How, his uncle's servant.