must creep along it and try and get a peep of our friend at home. I've watched that drawing-room window for a long time, and I believe that he makes it his business room."
Carefully he unfastened the French window, and bending low so as to escape the observation of any person passing by, we both crept along the narrow balcony until, by swinging from one balustrade to the other, we found ourselves standing over Hartmann's portico.
Even from where we stood we could hear voices. Forward we crept again until we were outside the windows of the drawing-room, crouching so that no inquisitive policeman could detect us.
The blind of the window at which I listened did not fit well, therefore, through the small crack, I was enabled to peer within. The room was a large, well-furnished one with a fire burning brightly; near it stood a large roll-top writing-table at which sat a fat, flabby, sardonic-faced man of about fifty-five. He had grey eyes full of craft and cunning, a prominent nose, and a short-cropped grey beard. Ray whispered that it was the great Hartmann.
Near the fire, seated nervously on the extreme edge of a chair, was a respectably dressed man, a German evidently, with his hat in his hand. The man presented the appearance of a hard-working mechanic, and was obviously ill at ease.
We watched them in conversation, but could not distinguish one single word of what was said. All we could gather was that the fat man was overbearing in his manner, and that the visitor was most humble and subservient against his will.
For a full half-hour we watched, but unable to gather anything further, we were compelled to return to the house next door and regain the street, where for still twenty minutes longer we waited for the visitor's exit. When at last he came forth we followed him to the corner of Knightsbridge, opposite the Hyde Park Hotel, where he boarded a motor-bus, from which he eventually descended at the corner of Gray's Inn Road walking thence to a house in Harpur Street, Bloomsbury, where we later on discovered he lodged, under the name of Leon Karff.
The nature of the mission entrusted to this man, if one had actually been entrusted to him, was a mystery, yet it was a curious fact that "Harpur Street" appeared upon that scrap of paper which to us was such an enigma.
Next morning at six o'clock, I was already idling, at the corner of Harpur Street and Theobalds Road, but not until three hours later did the foreigner emerge and walk toward Holborn. Thence he took a motor-bus back to Sloane Street, and calling upon Hartmann, spent another half an hour with him.
And afterwards he went straight home. It was then about noon, and having an engagement in Court, I was compelled to relinquish my vigil. But at a little after five Ray entered our chambers, exclaiming:
"As I expected! That man Karff has been to see Steinheim in the hospital. I was there awaiting him, believing that he might visit him. Apparently the injured man has given him certain instructions."
"About what?"
Ray shrugged his shoulders in blank ignorance. Then he said, "We have advanced one step toward the solution of the problem, my dear Jack. But we have not gone very far."
He took the copy of the cryptogram from my writing-table and again examined it. The figures "6.11" puzzled him. Many times he referred to them.
Four days passed, during which we kept strict observation upon Karff and followed him wherever he went. On the fifth day, Ray having spent all the morning watching him, to relieve him I walked along the Theobalds Road a few minutes before one and paused, as usual, before the oil shop at the corner. There was no sign of my friend, and though I waited through the whole of that cold afternoon and evening, continuing my wearisome vigil till midnight, yet he did not come.
Much surprised, I returned to New Stone Buildings, where I found a telegram from Ray, sent from Waterloo Station at three o'clock, telling me that all was right, and urging me to await further information.
This I did. For a whole week I possessed myself in patience, not knowing where Ray was or what had befallen him. That he was on the trail of a solution of the mystery was evident, but he sent me no word of his whereabouts.
It was apparent, however, that he was no longer in London.
Eleven days after his disappearance I one afternoon received another telegram, which had been handed in at Chichester, asking me to go at once to the Queen's Hotel at Southsea, where he would meet me at ten o'clock that night.
At the hour appointed I awaited him in my bedroom overlooking Southsea Common and the harbour, and at last he joined me. I saw by the serious expression upon his face that something unusual had happened.
"The fellow Karff has realised that I'm following him, Jack. Therefore you must take the matter up. He's in the service of a greengrocer in Queen Street, close to the Hard. I haven't yet discovered his game."
Thus there was left to me a very difficult matter, a mystery which I exerted every effort to unravel. For the next fortnight I watched the fellow incessantly, being relieved sometimes by the pretty daughter of the Admiral Superintendent, whose home was fortunately in the Dockyard. In all weathers and at all times we watched, but we failed to discover anything. Ray remained at the hotel impatient and inactive, and I must admit that more than once I was inclined to believe that he had been mistaken in his surmises. Leon Karff was, as far as we could discover, a hard-working foreigner, driven by force of circumstances into adopting the lowly calling of a greengrocer's assistant. His employer supplied with fruit and vegetables the officers' messes of several of the ships in the Dockyard, and on infrequent occasions he drove in the light cart with his master when on his rounds taking orders.
This round at last he was in the habit of making three times a week.
One Saturday morning, as I was idling along the Hard, I saw Karff and his master, a man named Mitchell, drive in past the policeman at the main gate. But though I waited for over three hours to watch their exit, they did not reappear.
Much surprised at this, I walked round to the Unicorn Gate, at Landport, where, on making judicious inquiries of the policeman on duty, I learnt that Mitchell had driven out – but alone! His assistant, he said, had been sent back on foot with a message through the main gate just when the dockyard men or "maties," as they are called, were leaving work at midday.
Now having stood at that gate when the throngs had poured forth, I was quite certain he had not emerged. But I kept my own counsel, and returned to Southsea, deep in my own reflections.
On taking counsel with Ray, he at once telephoned to Vera at Admiralty House, and an hour later we all three discussed the situation, it being arranged that the Admiral's daughter should contrive to admit us to the Dockyard that night, when all was quiet, in order that we might institute a search for the missing German.
Therefore, just before half-past eleven, we halted before the small private door in the Dockyard wall, used by the Admiral-Superintendent and his household, and as the clock struck the door opened, revealing Vera. Next instant we were within the forbidden zone.
The night was frosty and a good deal too bright to suit our purpose. Vera gave some instructions to her lover, pointing to a row of long, dark sheds with sloping roofs on the opposite side of the Dockyard, saying:
"If he's inside, he's almost certain to be hidden somewhere near No. 4 shed. But be careful of the police; they are very watchful over yonder."
And after refastening the gate she disappeared into the darkness.
In the deep shadows we both crept noiselessly forward, negotiating in safety a pair of lock-gates in the open, and pursuing our way until in the vicinity of the shed which the Admiral's daughter had pointed out we discovered
