The man standing there showed not the slightest trace of alarm. There was just the suggestion of a smile on his face, as if he felt confident of his position. Jack could even see that he was fingering a cigarette case, as if he were thinking more about tobacco than anything else. He advanced a little nearer to his pursuer, and the suggestion of a smile broadened to a look of absolute amusement.

"It seems to me that we have met before," he said, with an accent that left no doubt as to his nationality. "But I have just reminded you of the fact. The question is, what are you going to do?"

"Well, you are a very cool hand," Jack replied. "My obvious duty is to hand you over to the police for the attempted murder of Mr. Spencer Anstruther."

"Instead of which you are going to do nothing of the kind," the stranger replied. "Besides, you are quite wrong. I am prepared to admit the assault on Mr. Anstruther, but as to murdering him--nothing of the kind. Besides, you know perfectly well you are consumed with curiosity to know all about my mysterious self."

Jack smiled to himself despite the gravity of the situation. The stranger had hit off his thoughts exactly.

"You are naturally anxious to know," he said, "what happened to me after you were good enough to escort my unconscious body to Shannon Street police station. I see you are a little dubious as to whether I am the right man or not; but if you looked at me carefully, you would see there is no mistake whatever."

Jack advanced a few paces nearer the speaker, and surveyed him closely in the blinding light of the lantern. There was no doubt whatever that this was one and the same Nostalgo. There was a certain mark in the shape of a crescent scar on his chin, the same scantiness of eyebrow, and the same peculiar droop of the lids.

"I am quite satisfied that you are the same man," Jack said.

"That's all right," the stranger cried, eagerly. "Of course, I know quite well that you are deeply interested in this Nostalgo mystery, and good fortune has placed you in the position to find out all about it. Get rid of those fellows, and call me a hansom. As a guarantee of good faith, here is my card. The address leaves a great deal to be desired, but I assure you my quarters are a great deal more comfortable than the locality would convey. If you have not yet dined, perhaps you would not mind partaking of my bread and salt."

Jack did not hesitate a moment longer. It was, perhaps, playing it rather low down on the police, but it seemed almost a criminal folly to waste so golden an opportunity as this. If the man had been given in custody for the murderous assault upon Spencer Anstruther, there would be long and tedious investigations, which would not only delay the solution of the trouble, but perhaps scare away others who were more or less party to the mystery. After all said and done, Anstruther was not a penny the worse for his adventure, and no harm could be done in defeating the so-called ends of justice.

"You stay where you are," Jack said, "and I will see what I can do for you. The police are On three sides of the square, leaving this side open to me. It is only a matter of a little patience, and the thing is accomplished."

Jack emerged cautiously into the road and looked about him. So far as he could see the street was deserted, though he could hear the constables making signs to one another on the other three sides of the square. Whilst he was still debating in his mind what to do, an empty hansom crawled towards him. Jack ran back and signed to the driver not to stop.

"You can earn a sovereign if you like," he said. "Don't ask any questions, but do exactly what I tell you. Turn back, go just to the corner of the square, and then return slowly; when you are opposite the gates, pull up as if there was something the matter with your horse. Then a man will come out and jump into your cab. You are to drive him to the address which I am going to give you without asking any questions. Here is your sovereign, and now listen carefully to the address. That's all."

Jack returned hurriedly to the gardens, at the same time whistling loudly as if he had need of assistance. It was not long before the three constables came swarming over the railings, guided to the right spot by the flash of Jack's lantern.

"Now's your time," he whispered hurriedly. "There is a hansom waiting for you by the gate, and the driver knows exactly what to do and where to take you. He is already paid his fare."

The man Nostalgo smiled and vanished. It was an easy matter to satisfy the police that their quarry had eluded Masefield, and that he was still hiding somewhere in the gardens. Jack left them to their search presently under the plea that he had no further time to waste. He walked as far as Albany Street, and there took a cab to Mare Street, Hackney.

It was not a particularly desirable neighborhood, as the man Nostalgo had pointed out. The destination was a side street of great dingy houses, which a generation or two back had been inhabited by wealthy tradesmen and the like. Now the large houses had been cut up into small flats and tenements, and for the most part were occupied by artisans and the like. The gutter swarmed with children, disheveled-looking women stood gossiping on the door-steps; round a flaming gin palace a group of loafers had gathered. It seemed to Jack high time to dismiss his hansom, for evidently vehicles of that kind were not frequent visitors to the street. More than one of the loafers lounging heavily against the greasy walls looked pointedly at Jack, but he was not the class of man to be tackled single-handed, and therefore he was allowed to proceed unmolested to No. 14, where he asked for Mr. James Smith.

A surly-looking porter, evidently considerably the worse for drink, replied that Smith lived on the fifth floor.

"Not that I have ever seen him," he growled, propitiated by Jack's half-crown; "sort of secretive chap, only goes out after dark and all that sort of thing. Shouldn't wonder if the police came and walked off with him any day; but that's no business of mine, so long as he pays his rent regularly and don't give no trouble. Keeps a couple of servants, he does; but they ain't English, and we don't have no truck with them."

Unenlightened by this fragment of a biography, Jack made his way up the greasy staircase. There must have been scores of families living in the self-same house, for Jack could hear the cries of children, and an occasional oath from some angry man. He came at length to the fifth floor, the outer door of which was closed, and on this he knocked. He knocked a third time before the door was cautiously opened, and the sallow, almond-eyed face of a Chinaman peered out. Apparently the Celestial was satisfied as to his visitor, for he merely bowed and stood aside so that Jack might enter. Then the door was closed again and locked. There was another door at the end of a dingy passage, the walls of which had not been papered for years; but a passage through this revealed a different state of affairs entirely.

It was idle to enquire by what magic this thing............