Murphy might be spiritually as cringing a coward as he was physically a fearless desperado.

Hampton had known such cases before; he had seen men laugh scornfully before the muzzle of a levelled gun, and yet tremble when pointed at by the finger of accusation.

He had lived sufficiently long on the frontier to know that men may become inured to that special form of danger to which they have grown accustomed through repetition, and yet fail to front the unknown and mysterious.

Perhaps here might be discovered Murphy's weak point.
Without doubt the man was guilty of crime; that its memory continued to haunt him was rendered evident by his hiding in Glencaid, and by his desperate attempt to kill Hampton.

That knife-thrust must have been given with the hope of thus stopping further investigation; it alone was sufficient proof that Murphy's soul was haunted by fear.
"Conscience doth make cowards of us all." These familiar words floated in Hampton's memory, seeming to attune themselves to the steady gallop of his horse.