Judge Dee smiled bleakly.

The Ding mansion proved to be an imposing building.

Young Ding came out into the first courtyard to welcome the judge. As Judge Dee descended from his palanquin an old man with a shaggy grey beard came forward and presented himself as the coroner. In daily life he was the proprietor of a well known medicine shop.

Judge Dee announced that he would proceed directly to the scene of the murder. Headman Fang and six constables would go to the main hall and there set up a temporary tribunal and make the necessary preparations for the autopsy.

Candidate Ding invited the judge and his assistants to follow him.

He led them along a winding corridor to the back courtyard. They saw a charming landscape garden with artificial rocks and a large goldfish pond in the middle. The doors of the main hall stood wide open. The servants were busy clearing away the furniture.

Candidate Ding opened a small door on left and led them through a dark, covered corridor to a small yard of eight feet square, enclosed on three sides by a high wall. The wall opposite showed a narrow door of solid wood. One panel had been battered in. Young Ding pushed this door open and stood aside to let the judge pass.

A smell of stale candles hung in the air.

Judge Dee stepped over the threshold and looked around.

It was a fairly large room of octagonal shape. High up on the wall there were four small windows with panes of coloured glass that filled the room with a soft, diffused light. Above the windows there were two grated openings of about two feet square. This was the only ventilation; except for the door through which they had entered, there were no other openings in the wall.

A spare figure clad in a house robe of dark green brocade was slumped over the huge writing desk of carved ebony standing in the centre of the room, facing the door. The head leaned on the crooked left arm, the right hand was stretched out on the desk still holding a writing brush of red lacquer. A small skull cap of black silk had dropped to the floor exposing the victim's long grey hair.

The desk showed the usual array of writing implements. A blue porcelain vase with wilted flowers stood on a corner. On either side of the dead man there stood a copper candle stick; the candles had burned down entirely.

Judge Dee looked at the walls covered with bookshelves as high as a man can reach. He said to Tao Gan:

"Examine those walls for a secret panel. Inspect the windows and those openings there!"

As Tao Gan took off his outer robe preparatory to climbing on the bookshelves, the judge ordered the coroner to inspect the body.

The coroner felt the shoulders and arms. Then he tried to lift the head. The body had grown stiff. He had to turn it over backwards in the armchair in order to expose the dead man's face.

The unseeing eyes of the old general stared at the ceiling. He had a lean, wrinkled face, frozen in an expression of surprise. From his scraggy throat there emerged an inch of a thin blade, not thicker than half a finger. It had a curious hilt made of plain wood, not much thicker than the blade and only half an inch long.

Judge Dee folded his arms and looked down on the body. After a while he said to the coroner:

"Pull that knife out!"

The coroner had difficulty in getting a hold on the diminutive hilt. When he had it between his thumb and forefinger, however, it came out easily. It had not penetrated deeper than about a quarter of an inch.

As the coroner carefully wrapped up the short weapon in a sheet of oil paper he observed:

"The blood has thickened and the body is entirely stiff. Death must have ensued late last night."

The judge nodded. He mused:

"When the victim had barred the door he took off his ceremonial robe and cap that are hanging there next to the door, and changed into his house dress. Then he sat down behind the desk, rubbed ink and moistened his brush. The murderer must have struck shortly after, for the general had written only two lines when he was interrupted.

The curious fact is that there cannot have been more than a few moments between his seeing the murderer and the dagger being stuck in his throat. He did not even lay down his brush."

"Your Honour", Tao Gan interrupted, "there is one fact which is still more curious. I cannot see how the murderer entered this room, let alone how he left it!"

Judge Dee raised his eyebrows.

"The only way by which a person can enter this room", Tao Gan continued, "is by that door. I have examined the walls, the small windows above the bookshelves and the grated openings. Finally I examined the door itself for a secret panel. But there are no hidden entrances of any description!"

Tugging at his moustache Judge Dee asked Candidate Ding:

"Could the murderer not have slipped in shortly before or after your father entered here?"

Candidate Ding who had been standing with a glazed stare by the door now took a hold of himself and replied:

"Impossible, Your Honour! When my father came here he unlocked the door. He stood for a moment in the entrance while I knelt. Our steward stood behind me. Then I rose and my father closed the door. No one could have entered then or before. My father keeps that door always locked and he has the only key."

Sergeant Hoong bent over to the judge and whispered in his ear:

"We shall have to hear that steward, Your Honour. Yet even if we assume that the murderer somehow or other slipped in here unobserved, I cannot see how he went out again. This door was found barred on the inside!"

Judge Dee nodded. To Candidate Ding he said:

"You assume that this murder was committed by Woo. Can you point out anything that proves that he was in this room?"

Ding slowly looked round. He sadly shook his head and said:

"That Woo is a clever man, Your Honour, he would not leave any traces. But I am convinced that a further investigation will bring to light clear proof of his guilt!"

"We shall have the body removed to the main hall", Judge Dee said. "You will now go there, Candidate Ding, and see that everything is ready for the autopsy!"

JUDGE DEE PONDERS ALONE IN A DEAD MAN'S ROOM;

THE AUTOPSY BRINGS TO LIGHT THE CAUSE OF DEATH

As soon as Candidate Ding had left Judge Dee ordered Sergeant Hoong:

"Search the victim's clothes!"

The sergeant felt through the sleeves of the robe. He took from the right sleeve a handkerchief and a small set consisting of toothpick and earcleaner in a brocade cover. He found in the left sleeve a large key of intricate design and a cardboard box. Then he felt in the dead man's girdle but found only another handkerchief.

Judge Dee opened the cardboard box. It contained nine crystallised plums, neatly arranged in three rows of three. These sweet plums are a delicacy for which Lan-fang is famous. The cover of the box bore a strip of red paper with an inscription: "With respectful congratulations".

The judge sighed and put the box down on the desk. The coroner removed the writing brush from the stiff fingers of the body. Two constables entered, and the dead General was carried away on a stretcher of bamboo poles. Judge Dee sat down in the victim's armchair. "You will all go to the main hall", he ordered. "I shall stay here for a while."

When the others had gone the judge leaned back in the chair and looked pensively at the bookshelves loaded with books and documents. The only empty wall space was on both sides of the door. It was flanked by scroll paintings, and above it there hung a horizontal board with the engraved inscription: "Studio of Self-examination". This evidently was the name that old General Ding had bestowed on his library.