Below the tower base is a dotted passageway marked "Main Control Node Entrance, three zhang deep, sloping northward." At the end of the passageway is a circle with the character "Control" written inside.
"It was drawn by Meng Qi," A Yao said, pointing to the signature in the lower right corner of the drawing. "He knew back then that there was a main control node beneath the radar station."
"Then why didn't he do anything about it?" Snow Empress asked.
"It's not written in the notes. Maybe this node wasn't exposed before the Spirit Vein Bureau withdrew. Or maybe he couldn't control it." A Yao turned the blueprint over; there was another line of small print on the back, the ink much lighter than on the front, as if it had been added later. She looked at it closely for a while, then read it aloud, "The node has three layers of protection, requiring three Spirit Vein Key to open. The keys are stored at the top of three Vein Eye pillars."
"Three keys, stored atop three stone pillars at the three Vein Eye," Snow Empress repeated. "We've already opened three Vein Eye. Are there keys atop the stone pillars?"
A Yao shook her head. "We didn't pay attention to the top of the stone pillar when we were Vein Eye. We only cleaned the groove at the bottom."
The Vein Guardian, standing at the door of the archives, overheard this and interjected, "There's a groove on top of the third stone pillar with a piece of iron stuck inside. I always thought it was a fragment of an old tool and never touched it."
A Yao glanced at him. "What kind of metal piece is that?"
"It's about the size of a palm, and it has patterns on it. Similar to the symbols on your bamboo canes."
A Yao rolled up the blueprint. "Go back and get it. There are three keys; one is at the third location. There might also be some on top of the stone pillars at the first two locations."
Snow Empress took the blueprints and glanced at the small print on the back. "Don't rush back. Old Dao's men already know the radar station's location. If they've found similar blueprints, they've probably already gone to find the keys. We have to get there before them."
" The Vein Guardian said that Old Dao's men went north last year," A Yao said.
"Last year was last year. Back then, the Vein Eye weren't open yet, and the key might not have been activated. Now that all three Vein Eye are open, the key on top of the stone pillar will become visible. If Old Dao's men keep an eye on the Vein Eye, they'll know when to retrieve the key." Snow Empress spread the blueprints back on the table and pointed to a road north of the radar station. "This old patrol road leads to the back of the radar station. We'll take this road. We won't go through the main entrance; we'll sneak in from the back."
Deacon Sun brought in a pot of tea and placed it on the table. "The patrol road is still passable. I sent people to patrol the north side last month; the road isn't blocked, but the grass is overgrown. If you want to go, I'll take some men to clear the grass first."
"No need to clear it," Snow Empress said. "The tall grass will provide good cover. Prepare three sets of night-clothes for us, and bring a few ropes. That radar station tower looks quite tall; if the passageway is on the tower, we'll have to climb it."
Deacon Sun acknowledged and left. The Vein Guardian was still standing at the door, staring intently at an old map hanging on the wall. A Yao walked over and asked him, "What are you looking at?"
"Look at this map." The Vein Guardian pointed to the marker north of the Blind Zone on the map. "This map was drawn ten years ago. Back then, the boundary of the Blind Zone was here, but now it has shifted at least half a mile outward. The area outside the radar station was hard soil ten years ago, but now it's probably all softened by acid. If you take the patrol road, you might have to wade through acid for the last part."
"We have protective suits," Snow Empress said.
"Even with protective suits, we might not be able to get through." The Vein Guardian turned around. "There are hidden pits under the acid water. I stepped on one last year when I was chasing that red ribbon and almost fell in. You'll need to bring long bamboo poles to scout ahead."
A Yao picked up the bamboo cane. "This is long enough."
The Vein Guardian glanced at the bamboo cane. "Alright. A bamboo cane is better for probing than an iron rod; it won't get stained with acid."
That afternoon, the three of them packed their equipment: three sets of night-clothes, three pairs of thick-soled boots, three long ropes, two signal guns, and four spare indicators for the Earth Vein Compass. A Yao rewrapped the handle of her bamboo cane and added an iron band to the bottom to prevent it from getting worn out while scouting. Snow Empress sharpened her knife and wrapped the blade with cloth to prevent it from reflecting light at night. The Vein Guardian had no weapon, so Deacon Sun rummaged through the warehouse and gave him an old woodcutter's knife, its blade full of nicks, but the Vein Guardian held it in his hand, weighed it, and said it was handy.
After dark, the three set off from the dirt road on the north side of the town. Deacon Sun and his men trampled the grass between the town entrance and the patrol road to create a narrow path, making it easier to walk. When they reached the entrance of the patrol road, Deacon Sun stopped.
"Go north from here, and you'll reach the back wall of the radar station at the end. It's about five li (2.5 kilometers), and there's a section in the middle that's been flooded with acid, so you'll have to wade through it. I'll wait for you here. One shot with the signal gun means you're in trouble, two shots mean it's done. Three shots..." He paused, "... three shots and I'll take some men in to provide backup."
Snow Empress nodded. The three of them squeezed into the patrol path and were quickly swallowed up by the tall grass.
The patrol Dao Fruit difficult to traverse. The grass grew taller than a person, and the road surface underfoot was riddled with potholes from the grass roots. After walking for about two miles, the grass gradually shortened, and the ground began to soften. The Vein Guardian walked in the lead, using a machete to part the grass and probe the way. He suddenly stopped, squatted down, and touched the ground.
"We've reached the acidic area." He stood up. "Step on the hard parts, walk around the soft parts. Follow me, don't try to find your own way."
The acidic water area was a shallow puddle, the water a murky yellowish-green with an oily film on the surface. Only a few hard earthen embankments provided footholds between the puddles. The Vein Guardian walked steadily on these embankments, with A Yao and Snow Empress following behind, stepping in his footprints. The bamboo staff made muffled splashes in the water, occasionally hitting a hidden pit where it would sink; A Yao would then avoid that spot.
When they reached the middle of the acidic water area, the Vein Guardian suddenly stopped. He squatted down and pointed to a clump of flattened water plants ahead. "Someone walked by. The footprints are fresh, no more than half a day old."
Snow Empress crouched down to examine the shoes. The mud on the water plants wasn't completely dry yet, and the tread pattern on the soles was different from what she'd seen in the Blind Zone yesterday—it was finer, like a specially made anti-slip sole. " Old Dao's men. At least two."
"They arrived half a day earlier than us," A Yao said.
"Chase them." Snow Empress straightened up. "But they can't move fast. One wrong step in the acidic water and they'll sink. They might still be ahead, not out yet."
The three quickened their pace. The Vein Guardian, leading the way, moved much faster; he knew this acidic area like the backyard. After walking about half a mile, the acidic area came to an end, and the ground hardened again. The grass ahead grew taller, and a narrow path, worn into the grass, could be seen leading towards the radar station.
The Vein Guardian parted the grass and glanced inside, then turned back and said, "There are mud tracks on the narrow path; they went through here. Another mile ahead is the back wall of the radar station. There's a drainage ditch behind it, and the opening is big enough for a person to crawl through. I crawled through that opening last year."