t any rate," interrupted Hewitt, "you've got the number of the cab?"

"Here it is," Plummer answered, "and I've already set a man to get hold
of the cabman. You'd better note the number--92,873."

Hewitt duly noted the number, and advised me to do the same, in case I
should chance to meet the cab during the afternoon; and as we neared our
destination Plummer gave us the rest of the case in outline.

"In the office," he said, "I found them in a great state. A copy of the
code, or cypher, in which confidential orders and other messages are
sent to the fleet all over the world, and in which reports and messages
are sent back, had disappeared during the morning. It was in charge of a
Mr. Robert Telfer, a clerk of responsibility and undoubted integrity. He
kept it in a small iron safe, which is let into the wall of his private
room. It was safe when he arrived in the morning, and he immediately
used it in order to code a telegram, and locked it in the safe again at
10.20. Two hours later, at 12.20, he went to the safe for it again, in
order to de-code a message just received, and it was gone! And the lock
of the safe is one that would take hours to pick, I should judge. There
isn't a shade of a clue, so far as I can see, except this circumstance
of Mayes being seen leaving by Corder--just between Telfer's two visits
to the safe, you perceive. And of course there may be nothing in that,
except for the character of the man. And that's all there is to go on,
as far as I can see. I needn't tell you how important the thing is at a
time like this, and how much would be paid for that secret code by a
certain foreign Government. We have made hurried arrangements to have
certain places watched, and as soon as I have taken you to the office I
must rush off and make a few more arrangements still. But here we are."

Mr. Robert Telfer's room was at the side of a long and gloomy corridor
on the upper floor, and the door was distinguished merely by a number
and the word "Private" painted thereon. We found Mr. Telfer sitting
alone, and plainly in a state of great nervous tension. He was a man of
forty or thereabout, thin, alert, and using a single eye-glass. Plummer
introduced us by name, and rapidly explained our business.

"I told you the name of the party I am after, Mr. Telfer," Plummer said,
"and I went straight to Mr. Martin Hewitt, as being most likely to have
information of him. Mr. Hewitt, whose name you know already, of course,