The final story reveals that the Old Man himself is a criminal, due to some of his trademark knotted rope being found at crime scene, and thereby implies that he may be the mysterious "Bill Owen" the police are unable to locate.
The final story reveals that the Old Man's true identity as a criminal is revealed through the discovery of his signature rope knots at the crime scene, implying that he may be the elusive figure known as "Bill Owen," who remains unknown to the authorities.