ain skill as a
detective. That kind of professional work was fatal for the
intelligence. Merrington had a great reputation behind him, and his
knowledge of European criminals was probably unequalled, but his methods
of investigating the moat-house murder suggested that he was no longer
one of the world's greatest detectives, if, indeed, he had ever deserved
recognition in their ranks. Caldew recalled that his fame rested chiefly
on his wide experience rather than on the more subtle deductive methods
of modern criminology. It was said in Scotland Yard that when Merrington
was at the height of his reputation, twenty years before, his knowledge
of London criminals and their methods was so extensive that he could in
most cases identify the criminal by merely looking at his handiwork.

As a modern criminologist, Caldew believed that the less a detective
intruded his own personality into his investigations the better for his
chances of success. He did not think that the loud officialism of
Merrington was likely to solve such a deep, subtle crime as the murder
of Violet Heredith, and, consequently, he had the chance for which he
had waited so long. It now remained for him to prove that he could do
better than Merrington. He had sufficient confidence in his own
abilities to welcome the opportunity, but at the same time he believed
that he was confronted with a crime which would tax all his resources as
a detective to unravel.

Like Merrington, he had been struck by the strangeness of the murder.
All the circumstances were unusual, and quite outside his previous
experience of big crimes. He had also come to the conclusion that the
ease with which the murderer had found his way into the moat-house, and
afterwards escaped, pointed to an intimate knowledge of the place.

It would be too much to say that Caldew and Merrington reached different
conclusions by the same road. Up to a certain point their independent
deductions from the more obvious facts of the case were alike, as was
inevitable. In every crime there are circumstances and events which are
as finger-posts, pointing the one way to the experienced observer. But
their subsequent deductions from the outstanding facts branched widely,
perhaps because the younger detective did not read so much into
circumstances as Merrington. From the same facts they had reached
different theories about the murder. Merrington, by a process of minute
and careful deductions which he had place