with an inarticulate cry, and
at the same instant there came a loud knocking at the door behind
him. The sound reverberated through the empty house, filling the
place with awful echoes,--like those knocks at the gate of Macbeth's
castle the night of Duncan's murder. Richard stood petrified for a
second; then he hastily turned the key in the lock, and Mr. Taggett
stepped into the scullery.

The two men exchanged swift glances. The bewildered air of a
moment before had passed from Richard; the dullness had faded out of
his eyes, leaving them the clear, alert expression they ordinarily
wore. He was self-possessed, but the effort his self-possession cost
him was obvious. There was a something in his face--a dilation of the
nostril, a curve of the under lip--which put Mr. Taggett very much on
his guard. Mr. Taggett was the first to speak.

"I've a disagreeable mission here," he said slowly, with his hand
remaining on the latch of the door, which he had closed on entering.
"I have a warrant for your arrest, Mr. Shackford."

"Stop a moment!" said Richard, with a glow in his eyes. "I have
something to say."

"I advise you not to make any statement."

"I understand my position perfectly, Mr. Taggett, and I shall
disregard the advice. After you have answered me one or two
questions, I shall be quite at your service."

"If you insist, then."

"You were present at the examination of Thomas Blufton and William
Durgin, were you not?"

"I was."

"You recollect William Durgin's testimony?"

"Most distinctly."

"He stated that the stains on his clothes were from a certain
barrel, the head of which had been freshly painted red."

"I remember."

"Mr. Taggett, _the head of that barrel was painted blue!"_

XXVII

Mr. Taggett, in spite of the excellent subjection under which he
held his nerves, caught his breath at these words, and a transient
pallor overspread his face as he followed the pointing of Richard's
finger. If William Durgin had testified falsely on that point, if he
had swerved a hair's-breadth from the truth in that matter, then
there was but one conclusion to be drawn from his perjury. A flash of
lightning is not swifter than was Mr. Taggett's thought in grasping
the situation. In an instant he saw all his carefully articulated
case fall to pieces in his hands. Richard crossed the narrow room,
and stood in front of him.

"Mr. Taggett, do you know why William Durgin lied? He lied because
it was li