nergy about the fellow that would turn
into a sour discontent if his mind were not fully occupied with work
which it is accustomed to, and probably enjoys doing."

"Have you anything to suggest?" I asked.

"I have an idea," he replied; "but I haven't mentioned it because it
doesn't satisfy me at all. I have an idea that the man is some sort
of detective hard at work all the time. But I can't imagine what sort
of detective would take a house up here and keep himself as busy as
Hilderman appears to be over some case in the neighbourhood. I can't
imagine what sort of case it can be."

"What about a secret German naval base in the Hebrides?" I suggested.
"It's not by any means impossible or even unlikely that the Germans
have utilised the lonely lochs and creeks to some sinister purpose.
Many of the lochs are entirely hidden by surrounding mountains, which
come right down to the edge of a narrow opening, and make the place
almost unnoticeable unless you happen to be looking for it."

"There's something in that, certainly," Garnesk agreed; "but we must
remember he's been here since May. Surely our precious Government
would have managed to find what they wanted, and clear it out by this
time. Then again, did they suspect the base, or did they have a
general idea that war was coming so far back as May?"

"As to the war," Dennis put in, "we don't really know when the
authorities had their first suspicions."

"No," said I; "but I fancy it was not a very definite suspicion until
after the Archduke was assassinated. But look here, Garnesk, just let
us suppose Hilderman really is a Government detective in the guise of
an American visitor. Wouldn't he be just about the man we want, or do
you think it would make too much stir to take him into our
confidence?"

"Far too much," Garnesk replied emphatically. "It's not that he
would talk; but if he has been here all this time his opponents have
got wind of him long before this, and his arrival on the scene in
connection with our case would give any suspicious character the tip
to bolt. I should advise keeping in touch with Hilderman, learn as
much as you can about him, and be ready to run to him for help if you
come to the conclusion that he is the man to give it."

We sat down among the heather at the foot of the Mallaig Vec road, and
looked out over the harbour.

"Don't turn your heads," said Dennis quietly, "but glance down at the
pier."

"Yes," said Garnesk in a moment,