efully 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