Zhang Haike tilted his head back, carefully bent down, and pressed his head against the copper horse. After adjusting his position, he let out a breath and reached for his waist. He had a bottle of “Chazi Water” at his waist, a type of mixed strong acid. After unscrewing it, he carefully dripped some onto the back of the copper horse.

The strong acid immediately began to corrode the copper horse’s back, quickly eating away a large area and revealing the inner structure. Zhang Haike put away the “Chazi Water,” examined the spot where the acid had dissolved the surface, and reached in. Sure enough, the mechanism inside was complex; he could see hundreds of tightly stretched threads, and on one of the iron wires was a small round disc filled with tiny iron beads.

The small iron column was already heavily rusted, mottled like the surface of the moon, but it was still possible to discern that intricate patterns had once been engraved on these small iron beads.

“What kind of mechanism is this?” one person asked.

“A variant of the eighteen-string mechanism, much more complicated,” Zhang Haike replied. This round disc contained a balance device invented by Lu Ban; even a slight vibration would cause the disc to tilt. However, as soon as the weight of the disc changed and the small iron beads rolled out, the disc would immediately regain its balance. The small iron beads that rolled off the disc would hit the iron wires below, bouncing along, and each wire would trigger a mechanism. There were hundreds of wires here, and depending on which wires were touched as the beads bounced, seven or eight different mechanisms could be triggered at once.

After that, the disc would quickly regain its balance, which meant it could be triggered multiple times, with each trigger being random and completely unpredictable. It was said that such mechanisms were invented by Lu Ban, with eighteen variations, and later generations kept adding to it. Zhang Haike had once seen a mechanism with seventy-two wires, made by an old gentleman to demonstrate the function of the eighteen strings, but this was the first time he had seen one with hundreds of wires.

Zhang Haike let out a sigh of relief, grateful that he had taken this matter seriously and used the most troublesome but safest method. He turned back to ask the person pulling the steel cable if they could still hold on, and after receiving a positive answer, he held his breath, lit the fire stick again, and took out a magnet from his pouch, placing it above the disc. All the small iron beads were drawn to the magnet.

He then carefully moved the magnet away, placed it back in his bag, and rolled off the steel wire, landing on the ground next to the copper horse. The moment he landed, he saw the disc immediately react to the vibration and tilt slightly, but since there were no iron beads inside anymore, nothing happened.

The group fell silent for a moment, realizing that nothing had been triggered, and they all breathed a sigh of relief. One person said, “That was easy.”

Zhang Haike looked at the iron beads on the magnet, noncommittal. He was not skilled at dealing with such mechanisms, especially in a real ancient tomb, but it seemed that this time he had won the gamble.

After they packed up their things and prepared to continue searching, one person asked, “Should we call the muffled oil bottle down?”

“Why call him? He can’t do anything and we have to take care of him. He doesn’t even like us. Let him stay up there,” another person replied. “Let’s finish our business quickly.”

Zhang Haike thought for a moment and nodded. He didn’t think that the Silent Oil Bottle was a burden; rather, he felt that encountering such a complex and sharp mechanism as the first trap in the tomb meant that the other situations in the tomb were still unknown. At this point, he felt that being overly confident about their success was a bit premature, and having the Silent Oil Bottle above would still provide many conveniences.

The group approached the bronze horse, all seeing the “Eighteen Strings” trap mechanism for the first time. They leaned over to look into the melting hole and were taken aback by the dense threads inside. Zhang Haike couldn’t help but feel a bit proud; this was something he had deciphered, and he had made no mistakes. He felt quite accomplished. Just then, someone asked him, “There are hundreds of threads here; does that mean there are hundreds of mechanisms in this room?”

“What’s the matter?” Zhang Haike asked.

The speaker struck a match and threw it around the tomb, quickly illuminating the corners. He said, “How could there possibly be so much space here?”

Zhang Haike turned to look around the tomb. Indeed, most of the mechanisms in ancient tombs were large in size. The term “Eighteen Strings” referred to the fact that eighteen types of mechanisms were already at the upper limit in terms of size. Most of the additional mechanisms added later were variations of these eighteen types. For example, if one string could trigger quicksand, it could also give rise to variations such as poison smoke, mercury, and so on. However, if there were so many threads, it was clear that simple variations could not explain it.

“What do you think?” Zhang Haike realized that the other person was correct.

“It seems that we are not triggering hundreds of different mechanisms. I believe these hundreds of threads are connected to the same mechanism but activate different parts of it,” the person said. “It’s like the foreign puppet on strings, where the threads move different parts of the same body. This could explain the spatial issue.”

“Are you saying that after we trigger this mechanism, a wooden puppet might appear?”

“I’m just using that as a metaphor,” the person replied. “But I think the possible consequences of triggering this mechanism might be different from what we imagine; perhaps it’s not an offensive mechanism.”

“What could it be?” Zhang Haike asked.

“I don’t know; we can only find out after we trigger it,” the person said, stroking the horse’s four legs. “All the threads connect through these four horse legs to the ground, then radiate underground to connect with the mechanisms in this room. The mechanism room is in the area directly beneath us. The force of the iron pillar hitting the threads isn’t very strong, so this kind of transmission mechanism must be amplified in the mechanism room below. We should simulate the construction process of this room to see if we can access the mechanism room; this would give us more confidence about this space.”

After the person finished speaking, Zhang Haike felt something was wrong. He looked at the hole they had dug: “When we opened the wall, we didn’t see any mechanisms inside, so all these hundreds of variations should be right beneath our feet. It’s too dangerous to dig into the tomb from here; we need to go outside and start digging down from the soil again. This will take a long time, and if there are blue oak stones beneath the tomb, we might not be able to break through for a week.”

A few people suddenly felt a bit discouraged. One of them said, “After analyzing it back and forth, are we being too cautious? How about we go up to the theft hole, throw a small stone to hit those silk threads, and see what happens? If we keep discussing, we might just scare ourselves to death.”

Zhang Haike listened and thought this plan was feasible. They had indeed spent too much time in this tomb chamber and needed to make some progress.

The person who suggested going up to the theft hole lit a firecracker and placed it at the gap of the bronze horse. A few children from the Zhang family turned back and climbed up into the theft hole. The muffled oil bottle was at the turn of the theft hole, remaining silent, but it was clear he had heard everything that was just said, making the Zhang children feel a bit embarrassed.

The burning time of the firecracker was short. After everyone climbed up, Zhang Haike took out an iron ball from his bag. With a flick of his finger and a snap of his thumb, he sent the iron ball flying towards the glowing spot of the firecracker.

The iron ball whizzed through the flames and struck inside the bronze horse, producing a series of faint clinking sounds. Everyone held their breath, waiting for the mechanism to activate.

The Zhang family had excellent hearing. Once they held their breath, they all heard a series of rustling sounds, so faint that it was impossible to determine where they were coming from; an ordinary person would certainly not have heard it.

Three to five seconds later, suddenly, the entire tomb chamber shook, and everyone saw changes in the blue bricks on the ground.

In four places on the ground, the blue bricks had sunk in.

Zhang Haike quickly threw out the firecracker, and under the illumination of the flames, they discovered a downward passage appearing on the ground.

The passage seemed very steep, resembling a deep well leading underground.

“Unseen and unheard, what on earth is this place?” Zhang Haike muttered to himself, “What kind of mechanism is this?”