ing it and studying the blade absently. Presently Fuller, noticing
his absorption, began to chaff him about it.

"Well," he laughed, "have you compiled a complete history of the knife
and it's owner? If you're ready to sit an examination on the subject I
will constitute myself examiner, then we'll find who the knife belongs
to, and corroborate or contradict your conclusions."

"It's a very ordinary knife to find on board a boat, I should think,"
said Dennis.

"Oh come, Mr. Burnham," Hilderman joined in, "you mustn't wriggle out
of it. Surely you can answer Mr. Fuller's questions."

"If Mr. Fuller will allow me to put one or two preliminary questions
to him," Dennis replied, entering into the spirit of fun, "I am ready
to go into the witness-box and swear quite a number of fanciful
things."

"Come now, Fuller," chaffed Hilderman. "You must give him a run for
his money, you know. He is risking his reputation at a moment's
notice. I think you ought to let him ask you three questions, at any
rate."

"Fire away, Mr. Burnham," said our host. "I'll give you a start of
three questions, and then you must be prepared to answer every
reasonable question I put to you, or be branded publicly as an
unreliable witness and an incompetent detective."

Dennis puffed at his pipe and smiled, and I was surprised to see that
he really was bringing his mind to bear on the trivial problem with
all the acuteness he had in him.

"Well, in the first place," he asked, "do you stop in port very often
overnight, or for any length of time during the day?"

"I never stop in port longer than I can help," laughed Fuller, "or the
owner of that knife would probably take the opportunity of buying a
new one, and throwing this old thing away. All the same, I don't see
how that is going to help you."

"Ah," said Dennis, in bantering vein, "you mustn't expect me to give
away my process, you know. The secret's been in the family for years."

"What's your second question, Den?" I asked.

"Is there a hotel within reasonable distance of your house on Loch
Whatever-it-is, Mr. Fuller?"

"Loch Duich?" our host replied. "There's one about six miles by road
and eleven or twelve by the sea."

"I don't think I need ask you the third question, then," said Dennis.
"You can begin your examination now."

"Now, Mr. Burnham," Fuller commenced, "you quite understand that
anything you say will be taken down in writing, and may be used as
evidence against you?