Plummer's two plain-clothes men and I reached the neighbourhood of the
bank with a quarter of an hour to spare, or rather more. We dismissed
the cab at some little distance from the spot, and approached singly, so
that it was not difficult for us to slip in separately among the dozen
or fifteen clerks as they arrived. We passed directly into the manager's
room, the door of which opened into the space left for the public before
the counter. From this room the whole of the outer office was visible
through the glass of the partition. The manager, Mr. Blockley, a quick,
intelligent man of thirty-six or so, gave us chairs and pointed out how
best we could watch the counter without ourselves being observed.
"If a letter is sent," he said, "it will be brought here to me, of
course, and I will bring the messenger in. If a cheque is presented from
Mayes, I have told the cashier to slide that big ledger off his desk
accidentally with his elbow. That will be your signal, and then you can
do whatever you think proper. I don't think I can do any more than
that."
We took our positions and waited. I felt pretty sure that if Mayes sent
at all it would be early, for obvious reasons. And I was right, for the
very first customer was our man.
He stepped in briskly scarcely a minute after the manager had ceased
speaking, and I remembered having seen him waiting at the street corner
as I came along. He was a well-dressed, smart enough looking man, in
frock coat and tall hat. He took a letter-case from his pocket, picked
out a cheque from the rest of the papers in it, and passed it under the
wire grille of the counter.
The cashier took it, turned it over, and shifted mechanically to post
the amount in the book on his desk. As he did so his elbow touched the
heavy ledger which the manager had pointed out to us, and it fell with a
crash. The cashier calmly put his pen behind his ear, and stooped to
pick up the book, but even as he did it the two Scotland Yard men were
out before the counter, and had sidled up to the stranger, one on each
side.
"May we see that cheque, if you please?" asked one, and the cashier
turned its face toward him. "Ah, just so; a hundred pounds--Mayes. We
must just trouble you to come with us, if you please. There is some
explanation wanted about that cheque."
I had followed the two men from the manager's room, and now I saw that
while one had laid his hand on the stranger's shoulder the other had
taken him by the opposite arm. "Why," said the former, looking into his
face, "it's Broady Sims!"
"All right," the man growled resignedly. "It's a cop. I'll go quiet."
But as he spoke I saw the free hand steal out behind him and pitch away
a crumpled fragment of paper. One of the policemen saw it too, followed
it with his eyes, and saw me snatch it up.
"That's right, sir," he said, "take care of that; and we'll have a cab,
in case anything else drops accidentally. It's just a turning over,
Broady, that's what it is."
I spread out the piece of paper, and was astonished to find inscribed on
it just such another series of figures, in groups of eight, as was found
in the cypher message in the Case of the Lever Key.
Here was a great find--a secret message as clear to me as to Mayes
himself, and as likely as not the scrap of paper that would hang him! I
took one of the plain-clothes men aside while the other kept his hold of
Broady Sims.
"This is very important," I said. "It is a cypher message which Mr.
Hewitt can read--or I, myself, in fact, with a little time. Must you
take it with you? If so, I'll make a copy now."
"Well, sir, we're responsible, you see," the man said, "so I think we
must take it; so perhaps you'd better make a copy, as you suggest."
"Very well," I said, "that is done in a few seconds. You can take your
man off, and I will go direct to Mr. Hewitt and Inspector Plummer with
the copy." And with that I made the copy, which read thus:--
23, 19, 15, 1, 9, 14, 9, 2; 20, 8, 1,
20, 14, 14, 20, 8; 14, 5, 12, 4, 9, 7,
5, 14; 3, 8, 18, 23, 0, 14, 1, 8; 22,
9, 6, 1, 18, 3, 5, 1; 19, 14, 15, 21,
9, 0, 20, 12; 18, 12, 21, 1, 6, 23, 20,
12; 9, 18, 15, 5, 18, 13, 12, 20.
It struck me to ask the manager if the cheque just presented were one of
those procured from Mr. Trenaman the night before, and I found that it
was. Then I left the policemen with their prisoner and made for the
nearest cab-rank. This cypher message, no doubt conveying Mayes's
instructions to the man just captured, was probably of the utmost
importance, and Hewitt must see it at once; and as the cab ambled along
towards Barbican I busied myself in deciphering the figures according to
the plan of the knight's move in chess, as Hewitt had explained to me. I
could only see two noughts among the numbers, so plainly it was a longer
message than the one then deciphered--one of sixty-two letters, in fact.
I turned the figures into the letters corresponding in the alphabet, _a_
for 1, _b_ for 2, and so on, as Hewitt had done, and I arranged these
letters in the squares of a roughly drawn chessboard, so that they stood
thus:--
w s o a i n i b
t h a t n n t h
n e l d i g e n
c h r w 0 n a h
v i f a r c e a
s n o u i 0 t l
r l u a f w t l
i r o e r m l t
The letters thus set out, to read off the message was a simple task
enough, in view of the key Hewitt had given me. I began, as in the case
of the Lever Key message, at the right-hand top corner, and taking the
knight's move from _b_ to _e_ in the last square but one of the third
line, thence to _a_ at the end of the fifth line, and so to _t_ in the
seventh line, and from that to _r_ (fifth square in bottom line), _u_ in
seventh line and so on, in the order shown by the Lever Key message, a
copy of which I kept as a curiosity in my pocket-book. So I read the
message through, and I set it down thus:--
/#
_Be at ruin Channel Marsh to-night twelve; wait in hall for
instruc. Word final._
#/
The general meaning of this seemed clear enough. The man whom the
policeman had recognised as Broady Sims was to be at some spot--a ruined
building, it would seem--in a place called Channel Marsh, at midnight,
there to wait in the hall for instructions; no doubt for instructions
where to take the hundred pounds he was to have got from the bank. "Word
final" was not so clear, though I judged--and I think rightly--that it
meant that the word "final" was to be used as a password by which the
two messengers should know each other.
I was almost at my destination, and was cogitating the message and its
meaning, when the cab checked at some traffic in Barbican, just by the
"Compasses" public-house, and Mr. Victor Peytral hailed me and climbed
on the step of the cab.
"I was just going to see if Mr. Hewitt was at the place," he said, "and
if so to ask him for news. But I am rather in a hurry, and perhaps you
can tell me?"
"We are on the track, I think," I answered, "and I have just come across
this, which I am taking to Hewitt," and with that I showed him my
translation of the cypher, and gave him its history in half a dozen
sentences.
"That's good," Peytral answered. "I don't know Channel Marsh, do you?
But probably Mr. Hewitt does. I won't keep you any longer--I see you're
hurrying. But I hope to see you again before long."
He dropped off the step and disappeared, and the cab went on round the
corner by the "Compasses."
I found Hewitt and Plummer in the office where, on pretence of
bookbindery, I had first seen Mayes face to face the day before. They
were near the completion of their examination of this office and all its
contents, and soon would begin as systematically on the premises behind.
I gave Hewitt my copy of the cypher message, and my translation, with an
exact account of how it had come into my possession.
Martin Hewitt studied the message for a minute or two, and then relapsed
into grave thought. So he sat for some little time, while Plummer left
the room by the window and descended the ladder to speak with his men on
guard below.
Presently Hewitt looked up and said: "Brett, this message is most
important--probably as important as you suppose it to be. But at the
same time I believe you have made a great mistake about it."
"But I haven't misread it, have I? Is there any other way----"
"No, you haven't misread it; you've read every word as it was intended
to be read. But it is a very different thing from what you suppose it to
be."
"What is it, then?"
Martin Hewitt put the paper on the table and looked keenly in my face.
"It is a trap," he said. "It is a trap to catch _me_--unless I flatter
myself unduly."