cigar-case, Old Sharon is equally useful to you. He has an inbred
capacity for reading the riddle the right way in cases of mystery, great
or small. In short, he possesses exactly that analytical faculty to
which I alluded just now. I have his address at my office, if you think
it worth while to try him."

"Who can trust such a man?" Mr. Troy objected. "He would be sure to
deceive me."

"You are entirely mistaken. Since he was struck off the Rolls Old Sharon
has discovered that the straight way is, on the whole, the best way,
even in a man's own interests. His consultation fee is a guinea; and he
gives a signed estimate beforehand for any supplementary expenses
that may follow. I can tell you (this is, of course, strictly between
ourselves) that the authorities at my office took his advice in a
Government case that puzzled the police. We approached him, of course,
through persons who were to be trusted to represent us, without
betraying the source from which their instructions were derived; and we
found the old rascal's advice well worth paying for. It is quite likely
that he may not succeed so well in your case. Try the police, by all
means; and, if they fail, why, there is Sharon as a last resort."

This arrangement commended itself to Mr. Troy's professional caution. He
went on to Whitehall, and he tried the detective police.

They at once adopted the obvious conclusion to persons of ordinary
capacity--the conclusion that Isabel was the thief.

Acting on this conviction, the authorities sent an experienced woman
from the office to Lady Lydiard's house, to examine the poor girl's