Judge Dee slowly walked on to the first courtyard.

It was brightly illuminated now by dozens of large paper lanterns bearing the inscription 'The Tribunal of Poo-yang.'

Under the supervision of Sergeant Hoong and Chiao Tai the constables were busy adding pulleys to the cross beam of the bell tower.

When he saw the judge, Sergeant Hoong hurriedly came over to enquire about further developments.

Judge Dee noticed with satisfaction that the sergeant looked none the worse for his adventure under the bronze bell.

The judge described Lin Fan's arrest and the secret passage connecting his mansion with the temple.

While the sergeant assisted the judge in putting on his robes, Judge Dee said to Chiao Tai:

'Go to the farm of Lin Fan with five constables! There you will find the four constables who took over from you. Arrest all inhabitants of the farm. Also the people on the junk that is lying moored to the jetty. It is a long night for you, Chiao Tai, but I want all of Lin Fan's henchmen safely under lock and key!'

Chiao Tai answered cheerfully that he liked the excitement. He immediately began selecting five sturdy men from among the constables.

Judge Dee walked over to the bell tower.

The pulleys had been put in place. The heavy bell was slowly hauled up by strong cables till it hung in its normal position about three feet above the floor.

For a few moments Judge Dee surveyed the trampled area underneath. The bones had been scattered during the frantic half hour they spent trying to escape from their bronze prison.

'Chiao Tai has given you my instructions,' he said to the headman of the constables. 'I repeat that after you have collected the bones, the dirt and dust under the bell must be sifted with the greatest care. You may find other important clues. Thereafter you will help to search Lin Fan's mansion. Leave four constables on guard duty. Report to me tomorrow morning!'

Then Judge Dee and Sergeant Hoong left the Temple of Transcendental Wisdom. Their sedan chairs awaited them in the yard. They were carried back to the tribunal.

The next morning introduced a fine autumn day.

Judge Dee issued orders to the archivist to search in the land register for material relating to the Temple of Transcendental Wisdom and Lin Fan's mansion. Thereafter he had a late breakfast in the garden behind his private office, attended by Sergeant Hoong.

When the judge was once more seated at his desk and tea had been served, Ma Joong and Chiao Tai entered.

Judge Dee ordered the clerk to bring them a cup of tea also and then asked Ma Joong:

Well, was there any difficulty in apprehending Lin Fan's men?'

'All went very smoothly,' Ma Joong said with a smile. 'I found the steward lying unconscious where Your Honour had knocked him down. I turned him and Lin Fan over to the constables. Then we searched the entire mansion for others but found only one man, a burly ruffian who started to act a bit rough. With a little persuasion, however, he soon let himself be trussed up nicely. Thus we have four prisoners: Lin Fan, his steward, his henchman, and the old gatekeeper.'

'I have brought in one prisoner,' Chiao Tai added. 'It turned out that three people were living on the farm. All of them are simple Cantonese peasants. On the junk we found five men, that is to say the captain and four boatmen. The boatmen are just stupid sailors, but the captain has all the marks of a hardened criminal. I placed the peasants and the sailors in custody at the warden's house, but the captain I had taken to our jail here.'

Judge Dee nodded.

'Call the headman of the constables!' he ordered the clerk. 'Then go to Mrs Liang's house and tell her that I wish to see her as soon as possible.'

The headman respectfully greeted the judge and then remained standing in front of the desk. He seemed tired, but he had an unmistakably smug look on his face.

'In accordance with Your Honour's instructions,' he began importantly, 'we have collected the bones of Liang Ko-fa and placed them in a basket now in the tribunal. We carefully sieved the dirt under the bell but discovered nothing. Then, under my personal supervision, the entire mansion of Lin Fan was thoroughly inspected and the rooms sealed. Finally I myself examined the water passage under the trapdoor.

'I discovered a small flat-bottomed boat moored under the archway. I took a torch and poled it all along the passage. It ends in the river, just outside the Watergate. There I found another stone arch in the river bank, hidden under the overhanging bushes. This arch is so low that the boat could not pass underneath, but if one jumped into the water, one could easily wade through.'

Caressing his whiskers, Judge Dee gave the headman a sour look.

' You, my friend,' he said, 'showed remarkable zeal so late in the night! I regret that your exploration of the water passage did not yield any hidden treasure. I take it, however, that in Lin Fan's mansion there were a few small things lying about that you could transfer to your capacious sleeves. But restrain yourself, my man, lest some day you find yourself in trouble. You may go now!'

The headman hurriedly took his leave.

'That greedy rascal,' Judge Dee said to his lieutenants, 'brought to light at least how the steward succeeded in leaving the city the other day without attracting the attention of the guards on the Watergate. He evidently went by this underground passage and waded under the archway into the river.'

As he spoke the archivist came in. He bowed and placed a sheaf of documents before the judge saying:

'Following Your Honour's instructions early this morning, I searched the files of the land registration. I located these documents relating to Mr Lin Fan's possessions.'

'The first document,' he continued soberly, 'is dated five years ago and records Mr Lin Fan's purchase of the mansion, the temple, and the farm. All three belonged originally to Mr Ma, the landowner who now lives outside the eastern city gate.

'This temple had been the headquarters of a secret, unorthodox sect, which had been suspended by the authorities. Mr Ma's mother firmly believed in Taoist magic. She installed six priests in the temple and had them read masses for her dead husband. In the deep of night she had the monks perform magical séances, during which the souls of the dead were called up and she could converse with them by means of the planchette. She had a passage built between the two compounds so that she could visit the temple at any time.

'Six years ago the old lady died. Mr Ma closed the mansion but allowed the priests to stay in the temple on the understanding that they kept it in good repair. The priests could provide their own living by reading masses and selling amulets to the devout.'

The archivist paused and cleared his throat. Then he continued:

'Five years ago Mr Lin made enquiries about a site in the north-west corner of the city. Shortly after that he purchased the mansion, the temple and the farm, paying a good price. This is the deed of sale. Your Honour will find a detailed ground plan attached.'

The judge glanced through the deed and then unfolded the map. Calling his lieutenants to his desk, he said:

'One can well imagine that Lin Fan was prepared to pay a high price! This property was eminently suited for his smuggling plans.'

Judge Dee's long finger traced across the map.

'You see on this map,' he said, 'that at the time of the purchase the passage between the two compounds consisted of an open stairway; the iron door and the secret trapdoor were later added by Lin Fan. I don't see any indication of the underground water passage. For that we shall have to refer to older maps.'