's a post-card." He took the card from
his pocket, and gave it to Hewitt.

"There is nothing else to tell me, then?" queried Hewitt. "Are you sure
that you have forgotten nothing that has happened since you first
arrived--_nothing at all_?" There was meaning in the emphasis, and a
sharp look in Hewitt's eyes.

"No, Mr. Hewitt," Samuel answered, hastily; "there is nothing else I can
tell you."

"Then I will think it over at once. You had better go back quietly to
your office, and think it over yourself, _in case_ you have forgotten
something; and I need hardly warn you to keep quiet as to what has
passed between us--unless you tell the police. I think I shall take the
liberty of a glance over Mr. Denson's office, and since his office boy
still stays away, I will lend him my clerk for a little. He will keep
his eyes open if any callers come, and his ears too. Wait while I fetch
him."

II

It was at this point that my humble part in the case began, for Hewitt
hurried first to my rooms.

"Brett," he exclaimed, "are you engaged this afternoon?"

"No--nothing important."

"Will you do me a small favour? I have a rather interesting case. I want
a man watched for an hour or so, and I haven't a soul to do it. Kerrett
_may_ be known, and I _am_ known. Besides, there is another job for
Kerrett."

Of course, I expressed myself willing to do what I could.

"Capital," replied Hewitt. "Come along--you like these adventures, I
know, or I wouldn't have asked you; and you know the dodges in this sort
of observation. The man is one Samuel, a Jew, of 150 Hatton Garden,
diamond dealer. I'll tell you more afterwards. Kerrett and I are going
into the offices next door, and I want you to wait thereabout. Presently
I will come downstairs with him and he will go away. An hour or so will
be enough, probably."

I followed Hewitt downstairs. He took Kerrett with him and locked his
office door. I saw them both disappear within the large new building,
and I waited near a convenient postal pillar-box, prepared to seem very
busy with a few old letters from my pocket until my man's back was
turned.

In a very few minutes Hewitt reappeared, this time with a man--a Jew,
obviously--whom I remembered having seen already at the door of that
office more than an hour before, as I had passed on the way from the
bookseller's at the corner. The man walked briskly up the street, and I,
on the opposite side, did the same, a little in the re