f my presence in the room.

By the time I had finished my lunch I had thoroughly impressed his face
and personality upon my memory, and felt sure that, if necessary, I
should know him anywhere again. My labours, however, were by no means
over; in fact they were only just beginning. What I had against him so
far would scarcely be sufficient to justify our applying for a warrant
for his arrest. If I wanted to bring the crime home to him, it would be
necessary for me to connect him with it more closely than I had yet
done. But how to do this in the short space of time that was at my
disposal I could not see. The murderer, as I have already said, was no
ordinary one, and had laid his plans with the greatest care. He had
taken away the knife, and in all probability had got rid of it long
since. No one had seen him enter the house on the night in question, nor
had any one seen him leave it again. I was nearly beside myself with
vexation. To be so near my goal, and yet not be able to reach it, was
provoking beyond endurance. But my lucky star was still in the
ascendant, and good fortune was to favour me after all.

As I have already observed, when the crime had become known, the
permanent detective force had been most assiduous in the attentions they
had given it. The only piece of valuable evidence, however, that they
had been able to accumulate, was a footprint on a flower-bed near the
centre of the yard, and another in the hall of the house itself. Now it
was definitely settled, by a careful comparison of these imprints, that
the murderer, whoever he might have been, wore his boots down
considerably on the left heel, and on the inside. Now, as every
bootmaker will tell you, while the outer is often affected in this way,
the inner side seldom is. I noticed, however, that this was the case
with the man I suspected. The heel of his left boot was very much worn
down and on the inside. The right, however, was intact.

On leaving the Continental Hotel, I made my way to the Police
Commissioner's office, obtained an interview with him, and placed the
evidence I had gleaned before him. He was good enough to express his
approval of my endeavours, but was doubtful whether the case against the
Italian was strong enough yet to enable us to definitely bring the crime
home to the man.

"At any rate it will justify our issuing a warrant for his arrest," he
said, "and that had better be done with as little delay as possible.
Otherwise h