Yin Wujou leaned against the door for almost the time it takes to drink a cup of tea, making sure the aura hadn't reappeared, before slowly straightening up. He adjusted his breathing to bring his heartbeat back to a normal rhythm, then gently opened the study door and peeked out—the corridor was empty, the morning sun had already made the east-facing window paper even brighter, warm golden light slanted into the depths of the corridor, dust motes danced slowly in the beams of light, everything looked just like a peaceful morning should.
He didn't linger on the second floor. Yin Wujou tiptoed downstairs, climbed out of the window of the storage room, and landed in the holly bushes outside. He crouched behind the holly bushes and scanned his surroundings—the courtyard was still empty. The morning light illuminated the entire courtyard, covering the blue brick ground with a warm, golden glow. The shadows of the two old locust trees had shortened considerably; it was already close to noon.
He crouched low and retraced his steps back to the west wall, where he retrieved the end of the rope he had hidden earlier from the holly bushes and gave it a tug. The rope was still sturdy. He used the ivy to climb over the wall, slid down from the outside, and landed on the edge of the field outside. His knee hit a hard clod of earth when he landed, which hurt a little, but he ignored it and ran back to the row of withered bean trellises to squat down and catch his breath.
The sharp edges of the bronze plaque in his arms pressed against the panel on his chest, heavy as the weight of a promise. Yin Wujou sat on the dry earth behind the bean trellis, took out the plaque and examined it again—four characters on the front, two lines on the back, the bronze surface gleaming warmly in the increasingly bright sunlight. He turned the plaque over and over twice before putting it back in his arms, leaning against the earthen embankment behind him and closing his eyes for a while.
He suddenly remembered something—how long had he lingered in the study? It was still dark when he set out, but now the sunlight had filled the entire courtyard; it must have been around 9 AM. Snow Empress had said she would go in through the main gate to find the Supervisor and stall him for half an hour. His task was to obtain the token within that half hour and then retreat, waiting for her at the foot of the courtyard wall. But at this moment, he was outside the wall, while Snow Empress was still inside. He didn't know if she had gone in or if the Supervisor had already discovered the tampering with the secret compartment in the study.
Yin Wujou squatted behind the bean trellis for about half an hour, his gaze fixed on the direction of the main gate of the Imperial Astronomical Bureau. There was a guard at the gate, wearing a gray-blue black robe, with a short stick slung over his waist, leaning against the door frame and yawning. After yawning, he rubbed his eyes, straightened up and glanced into the courtyard, then shrank back behind the door frame, not seeming to have encountered anything unusual.
After a while, two figures, one tall and one short, suddenly emerged from the main gate. The taller one wore a dark blue official robe, was slender, and walked with steady, slow steps, his hands behind his back, his sleeves swaying gently with each step. The shorter one was a woman, wearing a gray-brown cloak, the hood of which was half-drawn, obscuring most of her face. But Yin Wujou recognized her at a glance by her gait and her slightly right-leaning weight distribution—it was the Snow Empress.
The two stopped at the door and exchanged a few words. Yin Wujou was too far away to hear what they said, but he saw the supervisor nod slightly, bow to Snow Empress in farewell, and then turn and walk into the courtyard. Snow Empress stood there for a while, and after the supervisor's figure disappeared into the depths of the courtyard gate, she took a few steps unhurriedly towards the village entrance, and then, using a low wall by the roadside as cover, quickly circled around to the bean trellis where Yin Wujou hiding.
"Did you get it?" she asked in a low voice as she crouched down behind the bean trellis. The hood of her cloak was pulled down, revealing a face slightly flushed by the sunlight.
"Got it." Yin Wujou took out the bronze plaque and handed it to her. Snow Empress took it, looked at the front and back, rubbed the engravings on the edge of the plaque with her thumb, nodded, and put it in her pocket.
"Is anything wrong?"
Yin Wujou hesitated for a moment. "After I got the token, just as I was about to leave, I sensed a faint aura following me outside the first-floor storage room. It was grayish-green, very faint, as if it had been deliberately suppressed. It followed me to the study door, paused for a while, and then dissipated on its own."
Snow Empress's expression darkened slightly. "Did you see the owner of that aura?"
"No. The entire time we only saw the aura itself; we didn't see any human form or physical entity."
"Grayish-green..." Snow Empress frowned, seemingly searching her mind for the corresponding color of Spiritual Power. "The range is too broad. The color of Spiritual Power isn't fixed; the color displayed by the same person using different techniques, in different states, and at different times will vary. There are at least a dozen possible ranges for grayish-green. Do you remember the texture of that aura? Was it heavy or light? Did it remind you of anything?"
Yin Wujou closed his eyes and recalled the feeling of that aura moving from the stairwell along the corridor towards the study, like water crawling on a slope—slow and heavy, with a viscous texture. "Heavy," he said, "Like thick porridge slowly flowing in a tilted plate, not like the Spiritual Power leaking out when a living person walks, but more like the lingering aftertaste of something that has been soaking in a place for a long time."
"Soaked..." Snow Empress repeated the two words softly, her gaze suddenly sharpening. "The storeroom. That aura is seeping in from the direction of the storeroom. The Imperial Astronomical Bureau's spiritual vein storeroom contains a large number of ancient spiritual artifacts, some of which have been stored there for hundreds of years. The overflowing Spiritual Power has permeated the surrounding walls and floor. What you're sensing is probably residual energy from the storeroom's overflow—drifting through the gaps in the spiritual vein network."
Yin Wujou thought about it and felt that this explanation made sense. But the way that aura stopped and dissipated outside the study door—it seemed too much like a conscious judgment and retreat, not like the random drifting of residual Spiritual Power. "Would residual energy stop outside the door on its own before dissipating?"
Snow Empress fell silent as well. She crouched behind the bean trellis, her fingers unconsciously twirling a tassel on the edge of her cloak, her gaze lingering for a long time on the distant wall of the Imperial Astronomical Bureau. "No," she finally said, "Residual energy can't judge for itself. That energy either has an owner, or it's being manipulated by some other Spiritual Power. Either way, it means there are more than just the two of us moving within the Imperial Astronomical Bureau."
She stood up and brushed the dirt off her knees. "Let's go. Don't rush into the warehouse. Let's find a place to go over the situation and plan from the beginning, and figure out the source of that scent first. It's too dangerous to rush in."
The two riders rode along the country path towards the edge of the village, bypassing the walls of the Imperial Astronomical Bureau and the early-rising villagers, finally stopping beside an abandoned brick kiln in the western suburbs. Most of the kiln had collapsed, leaving only a few crooked cave dwellings. The entrances were overgrown with waist-high mugwort and hyssop, and the walls were covered with a thick layer of old tobacco ash, so black that a wisp of ash would fall off with a touch. Yin Wujou tied his horse to a withered jujube tree outside the cave dwelling and followed Snow Empress into the innermost, relatively intact cave dwelling.