ck them up."

"Certainly, Mr. Jacox," she said. "Jack is intensely anxious. He's very
puzzled as to what they intend doing."

"Yes," I replied, "it's quite a mystery. But we shall discover something
ere long, never fear."

Vera laughed as she sipped the glass of milk I had ordered.

Then I briefly explained all that I had discovered, telling her how the
two men had evidently taken the factory on a lease, and how they were
there every day, apparently making plans for future business.

"But what business do they intend starting?" she asked.

"Ah!" I said; "that's what we have to find out. And we shall do so
before very long, if we are careful and vigilant."

"Trust me," she said; "I am entirely at your orders."

"Then I shall wait and hear your report," I said. "When you return to
the hotel send a line to my room."

And with that arrangement we parted.

That day I spent idling in the vicinity of the hotel. It was mid-August,
and the atmosphere was stifling. That district of Hull is not a very
pleasant one, for it is one of mean provincial streets and of the noise
of railway lorries rumbling over the granite setts.

The afternoon I spent in playing billiards with the marker, when about
six o'clock a page-boy brought me a note from my enthusiastic little
friend.

"I shall be in the station refreshment-room at half-past six. Meet
me.--VERA."

Those were the words I found within the envelope.

Half an hour later, when I sat at the little marble-topped table with
her, she related how she had been following the pair all day.

"They were in the factory from half-past one until four," she said.
"They've ordered a builder to put up ladders to examine the chimney.
They appear to think it isn't quite safe."

She told me the name of the builder, adding that the contract was to
have the ladders in position during the next three days.

"They are leaving for London to-night by the last train," she added. "I
heard the Belgian telling the hall-porter as I came out."

"Then we'll wire to Ray to meet them, and keep an eye upon them," I
said. "I suppose you will go up to town?"

"I think so. And when they return I will follow them down if Ray deems
it best," replied the pretty girl, who was just as enthusiastic in her
patriotism as ourselves.

So still mystified I was compelled to remain inactive in Hull, while
Vera and the two foreigners whom we suspected of espionage went up to
London.

For the next four days I h