admitting that he was engaged in the illicit traffic of
liquor, when apparently, the police were not at all concerned with
this phase of his activities.

"But aside from all this, there is the watch; the watch is very
important. It may be negative, it is true, but it is nevertheless
very convincing. The rope and the twine and the fish line were
positive evidence. Not evidence that the murderer owned the farm
or farmyard perhaps, but evidence that the articles in question
were at that farmyard a considerable time; evidence that the twine
was in a hat factory.

"Place the rope, twine and fish line in Boyle's possession; place
Boyle in a hat factory and you may convince me of his guilt of
Miller's murder. Not otherwise."

He snapped shut the watch case, with an emphatic click. His brow
cleared.

"Negative evidence is often very important, is it not? It helps
clear one's mind. I think I am beginning to see. What a gorgeous
plan it was. Did I say that I took back what I said about the man,
responsible for these deaths not being subtle? I did? Well he is
subtle, dangerously so."

"Do you mean, Professor," Jimmy leaned forward eagerly, "that you
know the man who--"

"Not so fast young man. I do not know who it is, but I am
beginning to think I know who it might be; who it can be. Is that
dubious?" His eyes were now gleaming. The three men watching him
knew the signs. His small shapely hand was pounding the arm of his
chair softly. He became suddenly grave. He spoke to McCall:

"Did we hear Flynn say that he told his comrades when he came here
that he would have to leave on an important errand today?"

McCall and Jimmy nodded. Professor Brierly's gravity became more
profound. He sprang to his feet. He said emphatically:

"Call New York at once, Mr. McCall. Do not waste a minute. Tell
them to take extreme precautions in watching Flynn. I believe
Flynn is in the greatest danger. Oh, fool that I am! Why did I not
think of it? At once, Mr. McCall, at once." He pounded the table
impatiently. As McCall was turning the small crank to ring the
operator, Professor Brierly added:

"After you've done that, McCall, see if you can get in touch with
the train that Flynn took. Warn his guards."

When McCall came back to the table looking inquiringly toward the
white-headed old scientist, the latter smiled slowly. "Thinking
that I am getting into my dotage, young man? Flynn is in deadly
danger. I will feel at ease about him on