empty factory,
a place which was not very large, but which possessed a very high
chimney.

The managing clerk entered the premises with a key, and for about half
an hour the pair were within, apparently inspecting everything.

I was puzzled. Why they were in treaty to rent a place of this
description was an utter enigma.

They returned to the hotel to luncheon, and I watched them engaged in
animated discussion afterwards, and I also noticed that they despatched
a telegram.

Next day they called upon the solicitor, and by their satisfied manner
when they came forth from the office, I guessed that they had become
tenants of the place.

In this I was not mistaken, for that same afternoon they went together
to the factory and let themselves in with the key, remaining within for
over an hour, evidently planning something.

That night I wrote a long report to Raymond, and next morning spoke to
him over the telephone.

"Vera wants to know if you want her in Hull. If so, she'll come," my
friend said. "I'm just as puzzled as you are. Those two men mean
mischief--but in what manner is a mystery."

"If Miss Vallance can come, I'll be only too thankful," I replied. "I
fear the men know you, but they don't know her. And she can greatly
assist me."

"Very well, Jacox," was his reply. "She'll leave this evening. She'll
wire to the hotel. She'd better not be seen with you. So, to the hotel
people, you'll be strangers. Meet outside, and arrange matters. 'Phone
me when you want me up there."

"Right, old chap," I replied. "I'll ring you up at eleven to-morrow and
report. So be in. Good-bye."

And I rang off.

Vera arrived just before eleven that evening. I was in the hall of the
hotel when the porter entered, carrying her dressing-case. She passed me
and went to the office, but I did not acknowledge her. She wore a neat
dark blue travelling gown, well cut by her tailor, and a little toque
which suited her face admirably. She possessed perfect taste in dress.

Half an hour later I sent a note up to her room by a waiter, asking her
to meet me outside on the railway platform at ten o'clock next morning.

She kept the appointment, and in order to escape observation we entered
the refreshment-room.

"The numbers of the rooms occupied by the two men are sixty-eight and
seventy-two," I explained. "Perhaps it will be as well if you watch them
the whole of to-day. They are at present in the writing-room, so you can
at once pi