Ambler appeared to be much concerned regarding the poor man’s death. When we had first met beside his vegetable barrow in the London Road he certainly seemed a hard-working, respectable fellow, with a voice rendered hoarse and rough by constantly shouting his wares. But by the whispered words that had passed I knew that Ambler was in his confidence. The nature of this I had several times tried to fathom.

His unexpected death appeared to have upset all Ambler’s plans. He grunted and took a tour round the poorly-furnished chamber.

“Look here!” he said, halting in front of me. “There’s been foul play here. We must lose no time in calling the police—not that they are likely to discover the truth.”

“Why do you say that?”

“Because the poor fellow has been the victim of a secret assassin.”

“Then you suspect a motive?”

“I believe that there is a motive why his lips should be closed—a strange and remote one.” Then, turning to the old fellow who had been the dead man’s friend, he asked: “Do you know anyone by the name of Slade?”

“Slade?” repeated the croaking old fellow. “Slade? No, sir. I don’t recollect anyone of that name. Is it a man or a woman?”

“Either.”

“No, sir.”

“Do you know if Lanky Lane ever had visitors here—I mean visitors not of his own class?”

“I never ’eard of none. Lanky wasn’t the sort o’ chap to trouble about callers. He used to spend ’is nights in the Three Nuns wiv us; but he’d sit ’ours over two o’ gin. ’E saved ’is money, ’e did.”

“But look here,” exclaimed Ambler, seriously. “Are you quite certain that you’ve never seen him with any stranger at nights?”

“Never to my knowledge.”

“Well,” my companion said, “you’d better go and call the police.”

When the old fellow had shuffled away down the rickety stairs, Ambler, turning to me, said abruptly:

“That fellow is lying; he knows something about this affair.”

I had taken up the empty dram bottle and smelt it. The spirit it had contained was rum—which had evidently been drunk from the bottle, as there was no glass near. A slight quantity remained, and this I placed aside for analysis if necessary.

“I can’t see what this poor fellow has to do with the inquiry upon which we are engaged, Ambler,” I remarked. “I do wish you’d be more explicit. Mystery seems to heap upon mystery.”

“Yes. You’re right,” he said reflectively. “Slowly—very slowly, I am working out the problem, Ralph. It has been a long and difficult matter; but by degrees I seem to be drawing towards a conclusion. This,” and he pointed to the man lying dead, “is another of London’s many mysteries, but it carries us one step further.”

“I can’t, for the life of me, see what connection the death of this poor street hawker has with the strange events of the immediate past.”

“Remain patient. Let us watch the blustering inquiries of the police,” he laughed. “They’ll make a great fuss, but will find out nothing. The author of this crime is far too wary.”

“But this man Slade?” I said. “Of late your inquiries have always been of him. What is his connection with the affair?”

“Ah, that we have yet to discover. He may have no connection, for aught I know. It is mere supposition, based upon a logical conclusion.”

“What motive had you in meeting this man here to-night?” I inquired, hoping to gather some tangible clue to the reason of his erratic movements.

“Ah! that’s just the point,” he responded. “If this poor fellow had lived he would have revealed to me a secret—we should have known the truth!”

“The truth!” I gasped. “Then at the very moment when he intended to confess to you he has been struck down.”“Yes. His lips have been sealed by his enemy—and yours. Both are identical,” he replied, and his lips snapped together in that peculiar manner that was his habit. I knew it was useless to question him further.

Indeed, at that moment heavy footsteps sounded upon the stairs, and two constables, conducted by the shuffling old man, appeared upon the scene.

“We have sent for you,” Ambler explained. “This man is dead—died suddenly, we believe.”

“Who is he, sir?” inquired the elder of the pair, bending over the prostrate man, and taking up the smoky lamp in order to examine his features more carefully.

“His name is Lane—a costermonger, known as Lanky Lane. The man with you is one of his friends, and can tell you more about him than I can.”

“Is he dead?” queried the second constable, touching the thin, pallid face.

“Certainly,” I answered. “I’m a doctor, and have already made an examination. He’s been dead some time.”

My name and address was taken, together with that of my companion. When, however, Ambler told the officers his name, both were visibly impressed. The name of Jevons was well known to the police, who held him in something like awe as a smart criminal investigator.

“I know Inspector Barton at Leman Street—your station, I suppose?” he added.“Yes, sir,” responded the first constable. “And begging your pardon, sir, I’m honoured to meet you. We all heard how you beat the C. I. Department in the Bowyer Square Mystery, and how you gave the whole information to Sergeant Payling without taking any of the credit to yourself. He got all the honour, sir, and your name didn’t appear at the Old Bailey.”

Jevons laughed. He was never fond of seeing his name in print. He made a study of the ways and methods of the criminal, but only for his own gratification. The police knew him well, but he hid his light under the proverbial bushel always.

“What is your own opinion of the affair, sir?” the officer continued, ready to take his opinion before that of the sergeant of the Criminal Investigation Department attached to his station.

“Well,” said Ambler, “it looks like sudden death, doesn’t it? Perhaps it’s poison.”

“Suicide?”

“Murder, very possibly,” was Jevons’ quiet response.

“Then you really think there’s a mystery, sir?” exclaimed the constable quickly.

“It seems suspiciously like one. Let us search the room. Come along Ralph,” he added, addressing me. “Just lend a hand.”

There was not much furniture in the place to search, and before long, with the aid of the constable’s lantern, we had investigated every nook and cranny.

Only one discovery of note was made, and it was certainly a strange one.Beneath a loose board, near the fireplace, Jevons discovered the dead man’s hoard. It consisted of several papers carefully folded together. We examined them, and found them to consist of a hawker’s licence, a receipt for the payment for a barrow and donkey, a post-office savings bank book, showing a balance of twenty-six pounds four shillings, and several letters from a correspondent unsigned. They were type-written, in order that the handwriting should not be betrayed, and upon that flimsy paper used in commercial offices. All of them were of the highest interest. The first, read aloud by Ambler, ran as follows:—

“That’s curious,” I remarked. “Whoever wrote that letter was inciting Lane to conspiracy, and at the same time held you in fear, Ambler.”

My companion laughed again—a quiet self-satisfied laugh. Then he commenced the second letter, type-written like the first, but evidently upon another machine.

“Looks as though there’s been some blackmailing,” one of the constables remarked. “Who’s Bennett?”

“I expect that’s Bobby Bennett who works in the Meat Market,” replied the atom of a man who had accosted us at Aldgate. “He was a friend of Lanky’s, and a bad ’un. I’ve ’eard say that ’e ’ad a record at the Old Bailey.”

“What for?”

“’Ousebreakin’.”

“Is he working now?” Ambler inquired.

“Yes. I saw ’im in Farrin’don Street yesterday.”

“Ah!” remarked the constable. “We shall probably want to have a chat with him. But the chief mystery is the identity of the writer of these letters. At all events it is evident that this poor man Lane knew something to his detriment, and was probably trying to make money out of that knowledge.”

“Not at all an unusual case,” I said.

Jevons grunted, and appeared to view the letters with considerable satisfaction. Any documentary evidence surrounding a case of mysterious death is always of interest. In this case, being of such a suspicious nature, it was doubly so.

“Seems a bit brief, and to the point,” was the elder constable’s remark. “I wonder what is the affair mentioned by this mysterious correspondent? Evidently the fellow intended to bring off a robbery, or something, and Lane refused to give his aid.”

“Apparently so,” replied Ambler, fingering the last letter remaining in his hand. “But this communication is even of greater interest,” he added, turning to me and showing me writing in a well-known hand.

“I know that writing!” I cried. “Why—that letter is from poor Mrs. Courtenay!”

“It is,” he said, quietly. “Did I not tell you that we were on the eve of a discovery, and that the dead man lying there could have told us the truth?”