the enemy not a little. We got our first suspicions of Ainsworth from
a few incautious words that he spoke in one of our cabs."

"It's a splendid system, I should think, for discovering the
movements of your enemies," said Arnold, not without an uncomfortable
reflection on the fact that he was himself now completely in the
power of this terrible organisation, which had keen eyes and ready
hands in every capital of the civilised world. "But how do you guard
against treachery? It is well known that all the Governments of
Europe are spending money like water to unearth this mystery of the
Terror. Surely all your men cannot be incorruptible."

"Practically they are so. The very mystery which enshrouds all our
actions makes them so. We have had a few traitors, of course; but as
none of them has ever survived his treachery by twenty-four hours, a
bribe has lost its attraction for the rest."

In such conversation as this the time was passed, while the cab
crossed the river and made its way rapidly and easily along
Kennington Road and Clapham Road to Clapham Common. At length it
turned into the drive of one of those solid abodes of pretentious
respectability which front the Common, and pulled up before a big
stucco portico.

"Here we are!" exclaimed Colston, as the doors of the cab
automatically opened. He got out first, and Arnold handed the case to
him, and then followed him.

Without a word the driver turned his horse into the road again and
drove off towards town, and as they ascended the steps the front door
opened, and they went in, Colston saying as they did so--

"Is Mr. Smith at home?"

"Yes, sir; you are expected, I believe. Will you step into the
drawing-room?" replied the clean-shaven and immaculately respectable
man-servant, in evening dress, who had opened the door for them.

They were shown into a handsomely furnished room lit with electric
light. As soon as the footman had closed the door behind him, Colston
said--

"Well, now, here you are in the conspirators' den, in the very
headquarters of those Terrorists for whom Europe is being ransacked
constantly without the slightest success. I have often wondered what
the rigid respectability of Clapham Common would think if it knew the
true character of this harmless-looking house. I hardly think an
earthquake in Clapham Road would produce much more sensation than
such a discovery would.

"And now," he continued, his tone becoming suddenly much more
se