Five minutes after Ayscough had gone away with Dr. Mirandolet the hotel servant who had summoned him from Purdie's sitting-room knocked at the door for the second time and put a somewhat mystified face inside.

"Beg pardon, sir," he said, glancing at Purdie, who was questioning Melky Rubinstein as to the events of the evening in their relation to the house in Maida Vale. "Two ladies outside, sir--waiting to see you. But they don't want to come in, sir, unless they know who's here--don't want to meet no strangers, sir."

Purdie jumped to his feet, and putting the man aside looked into the dimly-lighted corridor. There, a few paces away, stood Zillah--and, half hidden by her, Mrs. Goldmark.

"Come in--come in!" he exclaimed. "Nobody here but Andie Lauriston and Melky Rubinstein. You've something to tell--something's happened?"

He ushered them into the room, sent the hotel servant, obviously in a state of high curiosity about these happenings, away, and closed the door.

"S'elp me!" exclaimed Melky, "there ain't no other surprises, Zillah? You ain't come round at this time o' night for nothing! What you got to tell, Zillah?--another development?"

"Mrs. Goldmark has something to tell," answered Zillah. "We didn't know what to do, and you didn't come, Melky--nobody come--and so we locked the house and thought of Mr. Purdie. Mrs. Goldmark has seen somebody!"

"Who?" demanded Melky. "Somebody, now? What somebody?"

"The man that came to her restaurant," replied Zillah. "The man who lost the platinum solitaire!"

Mrs. Goldmark who had dropped into the chair which Purdie had drawn to the side of the table for her, wagged her head thoughtfully.

"This way it was, then," she said, with a dramatic suggestion of personal enjoyment in revealing a new feature of the mystery, "I have a friend who lives in Stanhope Street--Mrs. Isenberg. She sends to me at half-past-ten to tell me she is sick. I go to see her--immediate. I find her very poorly--so! I stop with her till past eleven, doing what I can. Then her sister, she comes--I can do no more--I come away. And I walk through Sussex Square, as my road back to Praed Street and Zillah. But before I am much across Sussex Square, I stop--sudden, like that! For what? Because--I see a man! That man! Him what drops his cuff-link on my table. Oh, yes!"

"You're sure it was that man, Mrs. Goldmark?" enquired Melky, anxiously. "You don't make no mistakes, so?"

"Do I mistake myself if I say I see you, Mr. Rubinstein?" exclaimed Mrs. Goldmark, solemnly and with emphasis. "No, I don't make no mistakes at all. Is there not gas lamps?--am I not blessed with good eyes? I see him-- like as I see you there young gentleman and Zillah. Plain!"

"Well--and what was he doing?" asked Purdie, desirous of getting at facts. "Did he come out of a house, or go into one, or--what?"

"I tell you," replied Mrs. Goldmark, "everything I tell you--all in good time. It is like this. A taxicab comes up--approaching me. It stops--by the pavement. Two men--they get out. Him first. Then another. They pay the driver--then they walk on a little--just a few steps. They go into a house. The other man--he lets them into that house. With a latch-key. The door opens--shuts. They are inside. Then I go to Zillah and tell her what I see. So!"

The three young men exchanged glances, and Purdie turned to the informant.

"Mrs. Goldmark," he said, "did you know the man who opened the door?"

"Not from another!" replied Mrs. Goldmark. "A stranger to me!"

"Do you know Mr. Levendale--by sight?" asked Purdie.

"Often, since all this begins, I ask myself that question," said Mrs. Goldmark, "him being, so to speak, a neighbour. No, that I do not, not being able to say he was ever pointed out to me."

"Well, you can describe the man who pulled out his latch-key and opened the door, anyhow," remarked Purdie. "You took a good look at him, I suppose!"

"And a good one," answered Mrs. Goldmark. "He was one of our people--I saw his nose and his eyes. And I was astonished to see so poor-looking a man have a latch-key to so grand a mansion as that!--he was dressed in poor clothes, and looked dirty and mean."

"A bearded dark man?" suggested Purdie.

"Not at all," said Mrs. Goldmark. "A clean-shaved man--though dark he might be."

Purdie looked at Melky and shook his head.

"That's not Levendale!" he said, "Clean-shaven! Levendale's bearded and mustached--and I should say a bit vain of his beard. Um! you're dead certain, Mrs. Goldmark, about the other man?"

"As that I tell you this," insisted Mrs. Goldmark. "I see him as plain as what I see him when he calls at my establishment and leaves his jewellery on my table. Oh, yes--I don't make no mistake, Mr. Purdie."

Purdie looked again at Melky--this time with an enquiry in his glance.

"Don't ask me, Mr. Purdie!" said Melky. "I don't know what to say. Sounds like as if these two went into Levendale's house. But what man would have a latch-key to that but Levendale himself? More mystery!--ain't I full of it already? Now if Mr. Ayscough hadn't gone away--"

"Look here!" said Purdie, coming to a sudden decision, "I'm going round there. I want to know what this means--I'm going to know. You ladies had better go home. If you others like to come as far as the corner of Sussex Square, come. But I'm going to Levendale's house alone. I'll find something out."

He said no more until, Zillah and Mrs. Goldmark having gone homeward, and he and his two companions having reached a side street leading into Sussex Square, he suddenly paused and demanded their attention!

"I've particular reasons for wanting to go into that house alone," he said. "There's no danger--trust me. But--if I'm not out again in a quarter of an hour or so, you can come there and ask for me. My own impression is that I shall find Levendale there. And--as you're aware, Andie--I know Levendale." He left them standing in the shadow of a projecting portico and going up to Levendale's front door, rang the bell. There was no light in any of the windows; all appeared to be in dead stillness in the house; somewhere, far off in the interior, he heard the bell tinkle. And suddenly, as he stood waiting and listening, he heard a voice that sounded close by him and became aware that there was a small trap or grille in the door, behind which he made out a face.

"Who is that?" whispered the voice.

"John Purdie--wanting to see Mr. Levendale," he answered promptly.

The door was just as promptly opened, and as Purdie stepped within was as quickly closed behind him. At the same instant the click of a switch heralded a flood of electric light, and he started to see a man standing at his side--a man who gave him a queer, deprecating smile, a man who was not and yet who was Levendale.

"Gracious me!" exclaimed Purdie, "it isn't--"

"Yes!" said Levendale, quietly. "But it is, though! All right, Purdie-- come this way."

Purdie followed Levendale into a small room on the right of the hall--a room in which the remains of a cold, evidently impromptu supper lay on a table lighted by a shaded lamp. Two men had been partaking of that supper, but Levendale was alone. He gave his visitor another queer smile, and pointed, first to a chair and then to a decanter.

"Sit down--take a drink," he said. "This is a queer meeting! We haven't seen each other since--"

"Good God, man!" broke in Purdie, staring at his host. "What's it all mean? Are you--disguised?"

Levendale laughed--ruefully--and glanced at the mean garments which Mrs. Goldmark had spoken of.

"Necessity!" he said. "Had to! Ah!--I've been through some queer times-- and in queer places. Look here--what do you know?"

"Know!" cried Purdie. "You want me to tell you all I know--in a sentence? Man!--it would take a month! What do you know? That's more like it!"

Levendale passed a hand across his forehead--there was a weariness in his gesture which showed his visitor that he was dead beat.

"Aye, just so!" he said. "But--tell me! has John Purvis come looking for his brother?"

"He has!" answered Purdie. "He's in London just now."

"Has he told about that diamond?--told the police?" demanded Levendale.

"He has!" repeated Purdie. "That's all known. Stephen Purvis--where is he?"

"Upstairs--asleep--dead tired out," said Levendale. "We both are! Night and day--day and night--I could fall on this floor and sleep--"

"You've been after that diamond?" suggested Purdie.

"That--and something else," said Levendale.

"Something else?" asked Purdie. "What then?"

"Eighty thousand pounds," answered Levendale. "Just that!"

Purdie stood staring at him. Then he suddenly put a question.

"Do you know who murdered that old man in Praed Street?" he demanded. "That's what I'm after."

"No!" said Levendale, promptly. "I don't even know that he was murdered!" He, too, stared at his visitor for a moment; then "But I know more than a little about his being robbed," he added significantly.

Purdie shook his head. He was puzzled and mystified beyond measure.

"This is getting too deep for me!" he said. "You're the biggest mystery of all, Levendale. Look here!" he went on. "What are you going to do? This queer disappearance of yours--this being away--coming back without your beard and dressed like that!--aren't you going to explain? The police--"

"Yes!" said Levendale. "Ten o'clock this morning--the police-station. Be there--all of you--anybody--anybody who likes--I'm going to tell the police all I know. Purvis and I, we can't do any more--baffled, you understand! But now--go away, Purdie, and let me sleep--I'm dead done for!"

Within ten minutes of leaving them, Purdie was back with Lauriston and Melky Rubinstein, and motioning them away from Sussex Square.

"That's more extraordinary than the rest!" he said, as they all moved off. "Levendale's there, in his own house, right enough! And he's shaved off his beard and mustache, and he's wearing tramp's clothes and he and Stephen Purvis have been looking night and day, for that confounded diamond, and for eighty thousand pounds! And--what's more, Levendale does not know who killed Daniel Multenius or that he was murdered! But, by George, sirs!" he added, as high above their heads the clock of St. James's Church struck one, "he knows something big!--and we've got to wait nine hours to hear it!"