note. I swore that, and I'll swear
it again. But when it came to questions whether he had passed the note,
and whether he knew it was forged, that was quite out of my province."

"I can understand that," said Helen; "but you heard the trial; you are
very intelligent, sir, you must have formed some opinion as to whether he
was guilty or not."

The expert shook his head. "Madam," said he, "mine is a profound and
difficult art, which aims at certainties. Very early in my career I found
that to master that art I must be single-minded, and not allow my ear to
influence my eye. By purposely avoiding all reasoning from external
circumstances, I have distanced my competitors in expertise; but I
sometimes think I have rather weakened my powers of conjecture through
disuse. Now, if my mother had been at the trial, she would give you an
opinion of some value on the outside facts. But that is not my line. If
you feel sure he was innocent, and want me to aid you, you must get hold
of the handwriting of every person who was likely to know old Wardlaw's
handwriting, and so might have imitated it; all the clerks in his office,
to begin with. Nail the forger; that is your only chance."

"What, sir!" said Helen, with surprise, "if you saw the true handwriting
of the person who wrote that forged note, should you recognize it?"

"Why not? It is difficult; but I have done it hundreds of times."

"Oh! Is forgery so common?"

"No. But I am in all the cases; and, besides, I do a great deal in a
business that requires the same kind of expertise--anonymous letters. I
detect assassins of that kind by the score. A gentleman or lady, down in
the country, gets a poisoned arrow by the post, or perhaps a shower of
them. They are always in disguised handwriting; those who receive them
send them up to me, with writings of all the people they suspect. The
disguise is generally more or less superficial; five or six unconscious
habits remain below it, and often these undisguised habits are the true
characteristics of the writer. And I'll tell you something curious,
madam; it is quite common for all the suspected people to be innocent;
and then I write back, 'Send me the handwriting of the people you suspect
the least;' and among them I often find the assassin."

"Oh, Mr. Undercliff," said Helen, "you make my heart sick."

"Oh, it is a vile world, for that matter," said the expert; "and the
country no better than the town, for all it looks so sweet