Judge Dee halted in front of Tao Gan. He exclaimed excitedly: "I am a fool, Tao Gan! I have let myself be led around by my nose, that's what I've done! There's no need to assemble all the inmates, I know now where to find our man! Come along. I'll go to Master Sun's library. You'll wait for me on the landing over the temple!" He took the lantern and ran out, followed by Tao Gan.
The two men went down. They parted in the empty courtyard. Judge Dee crossed over to the west wing, passed through the portal of the refectory, and ascended the stairs to Sun's quarters. He knocked several times on the carved door, but there was no answer. He pushed, and found that the door wasn't locked. He went inside.
The library was in semi-darkness, the candles burning low. The judge went over to the narrow door behind the desk, which presumably led to Sun's bedroom. He knocked again. He pressed his ear against the door, but heard nothing. He tried to open it, but it was securely locked.
He turned round and pensively surveyed the room. Then he stepped up to the scroll with the diagram, and looked for a while intently at the round symbol of the two forces depicted at the top. He turned to the door and left. Giving the broken balustrade a brief look, he entered the passage leading east to the square landing over the temple hall.
The judge vaguely heard the murmur of prayers coming up from the temple-nave below. Tao Gan was nowhere to be seen. He shrugged his shoulders and took the corridor leading to the store-room. Its door was standing ajar.
He went inside and lifted his lantern high. The room was exactly as he had seen it the last time he was there looking for Mo Mo-te. But the double door of the antique cupboard in the farthest corner was standing open. He ran up to it, stepped inside and held his lantern close to the picture of the two dragons on the back wall. The round circle in between them was indeed the Taoist symbol of the two forces, but the dividing line was horizontal. When he had asked Sun about it, he had forgotten that it had been here that he had seen the circle thus divided. Tao Gan's remarks and the broken saucer had made him see the connection.
He now also saw what he hadn't noticed before, namely that there was a small dot in each half of the circle, the germ mentioned by Sun when he had explained the meaning of the symbol to him. Looking closer, the dots turned out to be in fact small holes, bored deeply into the wood. He tapped the circle with his knuckle. No, it wasn't wood, it was an iron disk. And a narrow groove separated it from the lacquered surface surrounding it.
He thought he knew what those two holes in a round metal disk meant. He lifted his cap and pulled the hairpin from his top-knot. Inserting its point into one of the holes, he tried to make the disk turn to the left. It didn't budge. Then he tried the opposite direction, holding the hairpin with two hands. Now the disk turned around. He could make it turn easily five times, then it seemed to get stuck. With some difficulty he succeeded in making it turn around four more times. The right half of the back wall of the cupboard started to move a little, like a door about to swing open. He heard vague sounds on the other side. He softly pushed the door shut again.
He stepped back into the room, ran out into the corridor and looked around on the landing. Tao Gan hadn't come yet. Well, he would have to do without a witness. He went back to the store-room, entered the cupboard, and pulled the door open.
He saw a narrow passage only three feet wide, running five feet or so to the right, parallel with the wall. With two quick strides he turned the corner. He looked into a small room, dimly lit by only one dust-covered oil lamp hanging from the low ceiling. A tall, broad-backed man stood bent over the bamboo couch that took up the back wall, rubbing it with a piece of cloth. On the floor the judge saw a kitchen chopper lying in a pool of blood.
XIX
The man righted himself and turned round. Seeing the judge standing there he said with a benign smile: "So you found this secret room all by yourself! You are a clever fellow, Dee! Sit down and tell me how you did it! You can sit there on the couch; I just cleaned it. But mind the blood on the floor!"
Judge Dee looked quickly at the life-size wooden statue of a naked woman that was standing in the corner. The plaster was peeling off, and where the left arm should have been there was only a ragged stump of worm-eaten wood. He sat down by the other's side and looked around. The room was scarcely six foot square, and contained no other furniture except the couch they were sitting on. In the wall in front of him was a round aperture, apparently an air-shaft. On his right he saw a dark niche. He said slowly: "I suspected there was a secret room here near the corner of the building, but judging by the depth of the window niches in the corridor, that was impossible. There didn't seem to be enough space for one."
"There isn't!" Sun said with a chuckle. "But a thick supporting wall is built on the outside against the corner of this building, and this snug little room is inside that wall. You can't see it from the other side of the ravine that runs along this side of the monastery, nor can you see it from the windows of the east wing opposite. The old builders knew their job, you see! What made you think there was a secret room here, Dee?"
"Only a lucky accident," the judge replied with a sigh. "Last night, shortly after my arrival here, a window blew open and I got a brief glimpse of this room. I saw you while you were moving that wooden statue which you had taken from the Gallery of Horrors. I only saw your back, and I mistook the smooth grey hair plastered to your head for a close-fitting helmet. And I thought the statue was a real woman. That was the hallucination I consulted you about."
"Well, well!" Sun said astonished. "So you consulted me about myself, so to speak!" He laughed heartily.
"That scene," Judge Dee continued with impassive face, "set me chasing after the actor Mo Mo-te, who wore such an antiquated helmet during his sword dance. I can't understand, though, why that window on the right there doesn't show on the outside. That is the window I must have seen."
"It is," Sun replied. "But it's a trick-window, you know. I can't claim any credit for it; it was there already when last year I discovered this useful little room. The shutters are, as you see, on the inside, and the panels of oiled paper on the outside are flush with the surface of the wall, and painted like bricks. Transparent paint was used, so that one can open the shutters at daytime and have light to see by, without any outside people noticing anything." He pensively caressed his short ringbeard and went on: "Yes, I remember now, last night I opened it to get some fresh air. The window is on the side away from the wind, you see. I didn't think it would do any harm, for I knew that the shutters of all the windows opposite were closed tightly because of the storm. When I heard one blow open, I quickly closed mine, but apparently I wasn't quick enough — I was a bit careless there, I fear!"
"You were even more careless when, during your explanation of the diagram in your library, you stated that the circle of the two forces is always divided vertically. I knew for certain that somewhere I had seen the circle with a horizontal dividing line, hut at that moment I didn't remember where and when that had been. If you had then told me that the circle might be represented in varying positions, I would have dismissed the subject from my mind, and forgotten all about it."
Sun hit his hand on his knee. He said with a smile: "Yes, now I remember you asking about that. I must confess that I hadn't thought at all about the secret lock when I was giving you my explanation. You are an observant fellow, Dee! But how did you manage to turn the disk around? It screws a vertical bar up and down along the side of the door, and it doesn't turn easily. There's a special key for it, you know!" He took from his bosom an iron hook with two protruding dents and a long handle. The judge saw that the dents would fit the two holes in the disk.