Ayscough had manifested a certain restiveness and dislike to the proceedings ever since his companion had induced him to enter the back door of Molteno Lodge--these doings appeared to him informal and irregular. But at Melky's sudden exclamation his professional instincts were aroused, and he started forward, staring through the opening in the bushes made by Melky's fingers.

"Good Lord!" he said. "You're right. One of the Chinamen!"

The full moon was high in a cloudless sky by that time, and its rays fell full on a yellow face--and on a dark gash that showed itself in the yellow neck below. Whoever this man was, he had been killed by a savage knifethrust that had gone straight and unerringly through the jugular vein. Ayscough pointed to a dark wide stain which showed on the earth at the foot of the bushes.

"Stabbed!" he muttered. "Stabbed to death! And dragged in here--look at that--and that!"

He turned, pointing to more stains on the gravelled path behind them-- stains which extended, at intervals, almost to the entrance door in the outer wall. And then he drew a box of matches from his pocket, and striking one, went closer and held the light down to the dead man's face. Melky, edging closer to his elbow, looked, too.

"One of those Chinamen, without a doubt!" said Ayscough, as the match flickered and died out. "Or, at any rate, a Chinaman. And--he's been dead some days! Well!--this is a go!"

"What's to be done?" asked Melky. "It's murder!"

Ayscough looked around him. He was wondering how it was that a dead man could lie in that garden, close to a busy thoroughfare, along which a regular stream of traffic of all descriptions was constantly passing, for several days, undetected. But a quick inspection of the surroundings explained matters. The house itself filled up one end of the garden; the other three sides were obscured from the adjacent houses and from the street by high walls, high trees, thick bushes. The front gate was locked or latched--no one had entered--no one, save the owner of the knife that had dealt that blow, had known a murdered man lay there behind the laurels. Only the rat, started by Melky's footsteps, had known.

"Stay here!" said Ayscough. "Well--inside the gate, then--don't come out-- I don't want to attract attention. There'll be a constable somewhere about."

He walked down to the iron-work gate, Melky following close at his heels, found and unfastened the patent latch, and slipped out into the road. In two minutes he was back again with a policeman. He motioned the man inside and once more fastened the door.

"As you know this beat," he said quietly, as if continuing a conversation already begun, "you'll know the two Chinese gentlemen who have this house?"

"Seen 'em--yes," replied the policeman. "Two quiet little fellows--seen 'em often--generally of an evening."

"Have you seen anything of them lately?" asked Ayscough.

"Well, now I come to think of it, no, I haven't," answered the policeman. "Not for some days."

"Have you noticed that the house was shut up--that there were no lights in the front windows?" enquired the detective.

"Why, as a matter of fact, Mr. Ayscough," said the policeman, "you never do see any lights here--the windows are shuttered. I know that, because I used to give a look round when the house was empty."

"Do you know what servants they kept--these two?" asked Ayscough.

"They kept none!" answered the policeman. "Seems to me--from what bit I saw, you know--they used the house for little more than sleeping in. I've seen 'em go out of a morning, with books and papers under their arms, and come home at night--similar. But there's no servants there. Anything wrong, Mr. Ayscough?"

Ayscough moved toward the bushes.

"There's this much wrong," he answered. "There's one of 'em lying dead behind those laurels with a knife-thrust through his throat! And I should say, from the look of things, that he's been lying there several days. Look here!"

The policeman looked--and beyond a sharp exclamation, remained stolid. He glanced at his companions, glanced round the garden--and suddenly pointed to a dark patch on the ground.

"There's blood there!" he said. "Blood!"

"Blood!" exclaimed Ayscough. "There's blood all the way down this path! The man's been stabbed as he came in at that door, and his body was then dragged up the path and thrust in here. Now then!--off you go to the station, and tell 'em what we've found. Get help--he'll have to be taken to the mortuary. And you'll want men to keep a watch on this house--tell the inspector all about it and say I'm here. And here--leave me that lamp of yours."

The policeman took off his bull's eye lantern and handed it over. Ayscough let him out of the door, and going back to Melky, beckoned him towards the house.

"Let's see if there's any way of getting in here," he said. "My conscience, Mr. Rubinstein!--you must have had some instinct about coming here tonight! We've hit on something--but Lord bless me if I know what it is!"

"Mr. Ayscough!" said Melky. "I hadn't a notion of aught like that--it's give me a turn! But don't I know what it means, Mr. Ayscough--not half! It's all of a piece with the rest of it! Murder, Mr. Ayscough--bloody murder! All on account of that orange-yellow diamond we've heard of--at last. Ah!--if I'd known there was that at the bottom of this affair, I'd ha' been a bit sharper in coming to conclusions, I would so! Diamond worth eighty thousand pounds--."

Ayscough, who had been busy at the front door of the house, suddenly interrupted his companion's reflections.

"The door's open!" he exclaimed. "Open! Not even on the latch. Come on!"

Melky shrank back at the prospect of the unlighted hall. There was a horror in the garden, in that bright moonlight--what might there not be in that black, silent house?

"Well, turn that there bull's eye on!" he said. "I don't half fancy this sort of exploration. We'd ought to have had revolvers, you know."

Ayscough turned on the light and advanced into the hall. There was nothing there beyond what one would expect to see in the hall of a well-furnished house, nor was there anything but good furniture, soft carpets, and old pictures to look at in the first room into which he and Melky glanced. But in the room behind there were evidences of recent occupation--a supper- table was laid: there was food on it, a cold fowl, a tongue--one plate had portions of both these viands laid on it, with a knife and fork crossed above them; on another plate close by, a slice of bread lay, broken and crumbled--all the evidences showed that supper had been laid for two, that only one had sat down to it: that he had been interrupted at the very beginning of his meal--a glass half-full of a light French wine stood near the pushed-aside plate.

"Looks as if one of 'em had been having a meal, had had to leave it, and had never come back to it," remarked Ayscough. "Him outside, no doubt. Let's see the other rooms."

There was nothing to see beyond what they would have expected to see-- except that in one of the bedrooms, in a drawer pulled out from a dressing-table and left open, lay a quantity of silver and copper, with here and there a gold coin shining amongst it. Ayscough made a significant motion of his head at the sight.

"Another proof of--hurry!" he said. "Somebody's cleared out of this place about as quick as he could! Money left lying about--unfinished meal--door open--all sure indications. Well, we've seen enough for the present. Our people'll make a thorough search later. Come downstairs again."

Neither Ayscough nor Melky were greatly inclined for conversation or speculation, and they waited in silence near the gate, both thinking of the still figure lying behind the laurel bushes until the police came. Then followed whispered consultations between Ayscough and the inspector, and arrangements for the removal of the dead man to the mortuary and the guardianship and thorough search of the house--and that done, Ayscough beckoned Melky out into the road.

"Glad to be out of that--for this time, anyway!" he said, with an air of relief. "There's too much atmosphere of murder and mystery--what they call Oriental mystery--for me in there, Mr. Rubinstein! Now then, there's something we can do, at once. Did I understand you to say these two were medical students at University College?"

"So Mr. Penniket said," replied Melky. "S'elp me! I never heard of 'em till this afternoon!"

"You're going to hear a fine lot about 'em before long, anyway!" remarked Ayscough.

"Well--we'll just drive on to Gower Street--somebody'll know something about 'em there, I reckon."

He walked forward until he came to the cab-rank at the foot of St. John's Wood Road, where he bundled Melky into a taxi-cab, and bade the driver get away to University College Hospital at his best pace. There was little delay in carrying out that order, but it was not such an easy task on arrival at their destination to find any one who could give Ayscough the information he wanted. At last, after they had waited some time in a reception room a young member of the house-staff came in and looked an enquiry.

"What is it you want to know about these two Chinese students?" he asked a little impatiently, with a glance at Ayscough's card. "Is anything wrong?"

"I want to know a good deal!" answered Ayscough. "If not just now, later. You know the two men I mean--Chang Li and Chen Li--brothers, I take it?"

"I know them--they've been students here since about last Christmas," answered the young surgeon. "As a matter of fact they're not brothers-- though they're very much alike, and both have the same surname--if Li is a surname. They're friends--not brothers, so they told us."

"When did you see them last?" asked Ayscough.

"Not for some days, now you mention it," replied the surgeon. "Several days. I was remarking on that today--I missed them from a class."

"You say they're very much alike," remarked the detective. "I suppose you can tell one from the other?"

"Of course! But--what is this? I see you're a detective sergeant. Are they in any bother--trouble?"

"The fact of the case," answered Ayscough, "is just this--one of them's lying dead at our mortuary, and I shall be much obliged if you'll step into my cab outside and come and identify him. Listen--it's a case of murder!"

Twenty minutes later, Ayscough, leading the young house-surgeon into a grim and silent room, turned aside the sheet from a yellow face.

"Which one of 'em is it?" he asked.

The house-surgeon started as he saw the wound in the dead man's throat.

"This is Chen!" he answered.