"And do you allege that there are actually German spies in England?"
asked the strange man.

"Most certainly. We have in England and Scotland more than five thousand
fixed agents, men of almost every nationality except German, and in
every walk of life, from humble labourers to men and women in good
positions, all of whom are collecting information at the order of the
German travelling agents, who visit them from time to time, collect
their reports, and pay them their salaries. French, Swiss, and Italians
are mostly employed," I said. "At the present time my friend Raymond has
under observation a German band, seven young fellows all army officers,
who are playing in the streets of Leeds, and at the same time making a
secret map of the water-mains of that city, in order that when 'the Day'
of invasion comes, the enemy will be able to suddenly deprive a densely
populated area of water."

"But have you any actual proof of this?" he inquired.

As he spoke the door opened, and there entered a pretty dark-haired girl
of twenty-two, wearing a light skirt and a pale pink evening blouse.

"Oh, dad!" she exclaimed, halting suddenly, "I'm sorry I didn't know you
had a visitor."

"I shan't be a moment, Nella dear," the curious-looking old man said,
and after a quick, inquisitive glance at me the girl withdrew.

"Well," exclaimed the Professor, with a smile, "I'm really very obliged
to you for troubling to come here to warn me, but I think, my dear sir,
that warnings are quite unnecessary. I haven't the slightest fear that
any attempt will ever be made to secure my secret"; and he rose
impatiently.

"Very well," I replied, shrugging my shoulders. "I have warned you,
Professor Emden. The Government will not admit the presence of spies
amongst us, and for that reason we are now collecting indisputable
evidence."

"Ah!" he laughed, "and you want me to help you, eh? Well, sir, I don't
believe in a word of this scare--so I must decline that honour."

"And you will take no unusual precaution to keep the truth out of the
hands of our enemies, eh?"

"I leave it to Joynson's of Sheffield," he said. "They've paid me a
large sum down and a royalty for the secret of my process, and it is
scarcely likely that they'll allow it to fall into other hands, is it?"

"They will not, but you, a private individual, may," I said.

"I think not," he laughed, and a moment later I descended the stairs,
passing his pretty daughter Nella on the