Zhang's column surged out of the town, stealing and pilfering from the common people in the usual way as they went.

They travelled without incident for two days. Then, about ten miles from a village named Twin Wells, they came upon two bare-breasted men sitting beneath a tree by the side of the road with a pair of fine horses standing nearby. Two of the soldiers went over.

"Hey!" one shouted. "These two horses look like official horses. Where did you steal them from?"

"We are peaceful citizens," said one of the men. "We wouldn't dare to steal horses."

"We are tired of walking. Lend them to us," the second soldier replied.

The two men stood up, walked over to their horses and untied the reins.

The soldiers walked haughtily over and were just about to take hold of the reins when the two men kicked their behinds, leapt onto the horses and galloped over to one of the carriages.

"Is Fourth Brother in there?" one shouted.

"Ah, Twelfth Brother!" Wen answered.

"Fourth Brother, we're leaving," the man replied. "But don't worry, we'll be back to rescue you soon."

The two men galloped away before the carriage's guards could attack.

The column lodged that night at a town called Clear Water Shop. Early the following morning, while most of the soldiers were still asleep, a scream was heard, and there was a moment of confusion. The two troop commanders, Cao and Ping went to investigate and found the bodies of more than a dozen soldiers lying where they had slept, each with a gaping gash in the chest. There was no indication of who had killed them.

The next evening, they rested at Hengshi. This was a large town, and the column filled three inns and many private houses besides. During the night, one of the inns caught fire. Zhang ordered the bodyguards to guard Wen and to heed nothing else in order to avoid being tricked. The flames rose higher and higher.

"Bandits!" Cao Neng cried as he ran into Zhang's room. "They're attacking!"

"Please go and direct operations yourself, General Cao," Zhang replied. "I am unable to leave this place."

Cao nodded and left.

From outside the inn came the sound of screams and shrieks, galloping horses, the crackle of the flames and the smash of roof tiles as they hit the ground. Zhang ordered two bodyguards onto the roof to keep watch, but told them not to get involved unless the enemy attacked the inn. The fire did not get out of control, and before long it was extinguished. The agitated clamour continued for a while, then gradually died down to the point where the sound of hooves could be heard as horses galloped off eastwards.

Cao, his face covered in soot, grease and blood, ran in to see Zhang again.

"The bandits have retreated," he reported.

"How many of our men have been killed and wounded?" Zhang asked.

"I don't know yet. Several…several dozen."

"How many bandits were captured?"

Cao's mouth fell open. After a moment, he said: "None."

Zhang grunted.

"Their faces were covered with cloth, and their kung fu was horrendous," Cao added. "But it's very strange, they didn't steal anything. All they did was kill our brothers. Just before they left, they threw down two hundred taels of silver for the innkeeper saying it was compensation for starting the fire."

"So you think they were bandits, do you?" Zhang said. "Tell everyone to get some rest, General Cao. We will start out early tomorrow."

Cao retired and went to see the innkeeper, whom he accused of being in collusion with the bandits and responsible for the murder of the soldiers. The innkeeper kowtowed and begged for mercy and finally gave Cao the two hundred taels of silver.

The next day, the soldiers were busy until noon before finally making a start. They passed through beautiful country of blue hills and green water, surrounded by dense vegetation on all sides. After travelling for about four hours, the road began to grow gradually steeper and high peaks rose on either side.

A horse came galloping down the road towards them and halted about ten paces in front of the column.

"Listen to me, all of you," the rider called out. "You have offended the demons. Turn back quickly and you will be spared. If you continue eastwards, each one of you Turtles will surely die."

The soldiers shuddered as they looked at the man. He was wearing clothes made of rough hemp bound at the waist with grass rope. His face was pale yellow and his eyebrows slanted upwards, just like the images of life-stealing spirits in the temples. The man spurred his horse forward and galloped down the mountain, passing beside of the column, and was gone. Suddenly, one of the soldiers in the rear-guard gave a cry, and fell to the ground, dead. The rest started in fright and gathered round to look, but there was no wound visible on his body. Terrified, they all began talking at once.

Cao Neng assigned two soldiers to stay behind and bury the dead man and the column continued up the mountain. Before they had gone very far, another horse approached them from in front, its rider the same man they had seen earlier.

"Listen to me, all of you," he called out. "You have offended the demons. Turn back quickly and you will be spared. If you continue eastwards, each one of you Turtles will surely die."

The soldiers wondered fearfully how the man could have made his way round in front of them again. They had clearly seen him go down the mountain and one glance confirmed that there were no short cuts back up the slope. The man spurred his horse forward and the soldiers shrunk from him as if he was a real demon.

One of the Imperial bodyguards, named Zhu, stuck out his sword to obstruct the man. "Slow down, friend," he said.

The man struck Zhu's shoulder with his right hand, and the sword clattered to the ground. Then he sped off down the mountain. As he passed the end of the column, the last soldier gave a shriek and fell to the ground, dead. The other soldiers stood staring foolishly, scared out of their wits.

Zhang went down to the end of the column to investigate.

"What is this fellow, a man or a ghost?" Zhu said. He pressed his wounded right shoulder, his face deathly pale. Zhang told him to undo his clothes and examined the large black swelling on his right shoulder. He ordered the troops to strip the dead soldier bare and examine him for wounds. When they turned him over, they found a similar black swelling on his back from which the shape of a hand could be vaguely discerned. The soldiers broke into an uproar as a shout of "The Demon's Mark!" The Demon's Mark!" went up. Zhang ordered that two soldiers be left behind to bury the dead man. Two were chosen from the ranks, but even when threatened with death, they refused to carry out the order. Zhang had no alternative but to order a halt and wait until the body was buried before continuing.

"Master Zhang, this fellow is very strange," said Bodyguard Rui. "How could he pass us by and then make his way back in front of us again?"

Zhang stood deep in thought for a while. "Brother Zhu and the two soldiers were obviously victims of Black Sand Palm Kung Fu," he said. "There are very few masters of Black Sand Palm kung fu in the underworld."

"If it's Black Palm kung fu, then the best is naturally the Taoist Priest Hui Lu, but he's been dead for many years," Rui said. "Could it be that his spirit has re-appeared?"

Zhang slapped his thigh. "That's it! That's it!" he cried. "They're Hui Lu's pupils. The Twin Knights that people call Black Death and White Death. I was trying to think of one person, so I couldn't work it out. All right, so we're up against them as well."

He had no way of knowing that the Chang brothers were also members of the Red Flower Society.

That night, the column stayed at Black Pine Village. Cao posted guards all around the village to keep careful watch, but next morning, not one of the soldiers on guard duty returned to report, and a detail sent to investigate found them all dead with a string of paper money tied round each of their necks. The rest of the soldiers were terrified, and more than a dozen immediately deserted, slipping stealthily away.