Ma Joong roared with laughter. He pushed Po Kai's cap down over his eyes, then he went up with Chiao Tai and whistled for a boat.

WHEN Ma Joong and Chiao Tai came back to the tribunal they saw a light in judge Dee's private office. They found him closeted there with Sergeant Hoong. His desk was piled with dossiers and document rolls.

The judge motioned them to sit down on the stools in front of the desk, then said, "Tonight I examined together with Hoong the magistrate's library, but we couldn't discover how the tea had been poisoned. Since the tea stove stands in front of a window, Hoong thought that perhaps the murderer had pushed a thin blowpipe through the paper window pane from outside, and had thus blown the poison powder into the pan with tea water. But when we went back to the library to verify this theory, we found that outside the window there are heavy shutters, which haven't been opened for months. That window gives onto a dark corner of the garden; therefore the dead magistrate used only the other window, in front of his writing desk.

"Just before dinner I received the four city wardens. They seemed rather decent fellows to me. The warden of the Korean settlement came also, a capable man. It seems that in his own country he is an official of some sort." The judge paused a while, glancing through the notes he had been making while talking with Hoong. "After dinner," he resumed, "I went over with Hoong the most important files in the archives here, and found that all the registers are kept carefully up to date." He pushed the file in front of him away, and asked briskly, "Well, how did it fare with you two tonight?"

"I fear we didn't de too well, magistrate," Ma Joong said ruefully. "Me and my friend will have to learn this job from the bottom up, so to speak."

"I have to learn it myself, too," Judge Dee remarked with a wan smile. "What happened?"

First Ma Joong reported what the owner of the Nine Flowers Orchard had told them about Tang and his assistant, Fan Choong. When he had finished judge Dee said, shaking his head, "I don't understand what is wrong with that fellow Tang; the man is in a terrible state. lie imagines he has seen the ghost of the dead magistrate, and that seems to have shocked him deeply. But I suspect there's something else, too. The man got on my nerves. I sent him home after I had taken my after-dinner tea.

"As to Fan Choong, we shouldn't attach too much value to what that innkeeper said. Those people are often prejudiced against the tribunal; they don't like our controlling the rice price, the enforcement of the taxes on liquor and so on. We'll form our own opinion of him when he has turned up again."

The judge took a few sips from his tea, then resumed.

"By the way, Tang told me that there's really a man-eating tiger about here. A week ago he killed a farmer. As soon as we have made some progress with the murder investigation, you two might have a try at getting that brute."

"That's a job we like, magistrate!" Ma Joong said eagerly. Then his face fell. After some hesitation he told about the murderous attack they thought they had witnessed on the bank of the canal.

Judge Dee looked worried. Pursing his lips, he said, "Let's hope the mist played you a trick. I wouldn't like to have a second murder on my hands just now! Go back there tomorrow morning and see whether you can't find out more from the people living in that neighborhood. Perhaps there is a quite normal explanation for what you saw. And we'll see whether someone is reported missing." Then Chiao Tai reported on their meeting with Yee Pen's manager, Po Kai, and gave a chastened version of their visit to the floating brothels. He said they had drunk a cup of wine there, and talked a bit with the girls.

To their relief the two friends saw that the judge seemed pleased with their reports.

"You didn't do badly at all!" he said. "You have gathered much information, and brothels are the meeting place of all the riffraff of a town. It is good that you know your way about there now. Let's see where exactly those boats are located. Sergeant, give me that map we were looking at."

Hoong unrolled a pictorial map of the city on the desk. Ma Joong rose and, bending over it, he pointed at the second bridge over the canal, east of the watergate in the southwest quarter.

"Somewhere near here," he said, "we saw that man in the litter. Then we met Po Kai in the restaurant here, and went by boat east, along the canal. We left by the other watergate."

"How did you get through there?" the judge asked. "Those watergates are always barred by heavy trellises."

"Part of that trellis is loose," Ma Joong replied. "A small boat can get through the gap."

"We'll have that mended first thing tomorrow," Judge Dee said. "But why are those brothels located on boats?"

"Tang told me, your honor," Hoong put in, "that some years ago a magistrate was serving here who didn't want any brothels inside the city. Thus they had to move to boats, moored in the creek outside the east city wall. After that prudish magistrate had been transferred they stayed there, because the sailors found it convenient. They could go there directly from their ships, without having to pass the guards at the city gates."

Judge Dee nodded. Caressing his side whiskers, he observed,

"That Po Kai sounds an ínteresting fellow, I'd like to meet him sometime."

"He may be a poet," Chiao Tai said, "but he's a clever customer all the same. He placed us at a glance as ex-highwaymen, and on the boat he was the only one who noticed they were beating up that girl."

"Beating up a girl?" Judge Dee asked, astonished.

Chiao Tai hit his fist on his knee. "The package!" he exclaimed. "What a fool I am! I had forgotten all about it! That Korean girl gave me a package that Magistrate Wang had entrusted to her." The judge sat up in his chair.

"That may prove our first clue!" he said eagerly. "But why did the magistrate give it to a common prostitute?"

"Well," Chiao Tai replied, "she says Magistrate Wang met her once when she had been hired to liven up a party in a restaurant, and the old scoundrel took a liking to her. He could not of course visit her on the boat, but he often had her spend the night with him here in his own house. One day, about one month ago, when she was about to leave in the morning, he gave her a package, saying that the most unlikely place was always the best for hiding something. He told her to keep it for him, and not to tell anybody about it; he would ask for it back when he needed it. She asked what was in it, but he just laughed and said it didn't matter. Then he grew serious again, and told her that in case something should happen to him, she was to hand it over to his successor:"

"Why then didn't she bring it to the tribunal after the magistrate had been murdered?" Judge Dee asked.

"Those girls," Chiao Tai replied with a shrug, "stand in deadly terror of the tribunal. She preferred to wait till someone from there would visit the boat, and I was the first who happened to come along. Here it is."

He took the flat package from his sleeve and gave it to the judge.

Judge Dee turned it around in his hands, then said excitedly, "Let's see what is inside!"

He broke the seal and quickly tore off the wrapping paper. They saw a flat box of black lacquer. The lid was decorated with a design of two bamboo stems and a cluster of leaves, beautifully molded in raised gold lacquer, and surrounded by an ornamental frame, inlaid with mother-of-pearl.

"This box is a valuable antique," Judge Dee said as he lifted the lid. Then he uttered a cry of dismay. The box was empty. "Somebody tampered with it!" he exclaimed angrily. He quickly took up the torn paper. "I have indeed much to learn," he added peevishly. "Of course I should have examined the seal carefully before I tore off the paper! Now it's too late."