to your
men in this room. Bring them in here and shut the door; I can look after
the office from across the corridor, you know. Ask them each to detail his
exact movements about the office this morning, and get them to recall each
visitor who has been here from the beginning of the week. I'll let you
know the reason of this later. Come across to me in a few minutes."

Hewitt took the key and passed through the outer office into the corridor.

Ten minutes later Mr. Dixon, having questioned his draughtsmen, followed
him. He found Hewitt standing before the table in the private room, on
which lay several drawings on tracing-paper.

"See here, Mr. Dixon," said Hewitt, "I think these are the drawings you
are anxious about?"

The engineer sprang toward them with a cry of delight. "Why, yes, yes," he
exclaimed, turning them over, "every one of them! But where--how--they
must have been in the place after all, then? What a fool I have been!"

Hewitt shook his head. "I'm afraid you're not quite so lucky as you think,
Mr. Dixon," he said. "These drawings have most certainly been out of the
house for a little while. Never mind how--we'll talk of that after. There
is no time to lose. Tell me--how long would it take a good draughtsman to
copy them?"

"They couldn't possibly be traced over properly in less than two or two
and a half long days of very hard work," Dixon replied with eagerness.

"Ah! then it is as I feared. These tracings have been photographed, Mr.
Dixon, and our task is one of every possible difficulty. If they had been
copied in the ordinary way, one might hope to get hold of the copy. But
photography upsets everything. Copies can be multiplied with such amazing
facility that, once the thief gets a decent start, it is almost hopeless
to checkmate him. The only chance is to get at the negatives before copies
are taken. I must act at once; and I fear, between ourselves, it may be
necessary for me to step very distinctly over the line of the law in the
matter. You see, to get at those negatives may involve something very like
house-breaking. There must be no delay, no waiting for legal procedure, or
the mischief is done. Indeed, I very much question whether you have any
legal remedy, strictly speaking."

"Mr. Hewitt, I implore you, do what you can. I need not say that all I
have is at your disposal. I will guarantee to hold you harmless for
anything that may happen. But do, I entreat you, do everything possible.