"On the Common Law side, on the contrary, we are brought into the world of human passion and emotion; one in which the issues of life or death are at stake. We will suppose that your father, in the plenitude of his powers, is retained as counsel against some adroit rogue, some swindling company promoter, for example, who up to that moment had managed to keep himself well on the right side of the law." They began to see light, and listened with the closest attention. "We will say this swindler, a more than usually clever rascal, is living in luxury with his ill-gotten gains, when he makes a slip that brings him within reach of the long arm of justice. One of his victims (or perhaps several in combination) brings an action against him for the return of the money he has inveigled out of him by his lying prospectuses. He employs big counsel to defend him, but your father wins his case. The wealthy rogue is forced to disgorge, finds his occupation gone, and is reduced to penury." Sheila nodded to show that she was following his argument. "I am assuming for a moment that it is a civil action, and that it disclosed sufficient evidence to justify his arrest on a criminal charge later on. I deduce that from the fact that he was not a convicted felon at the time of writing that letter, otherwise he would not have been able to write and send it to your father. The meaning of the words `forced me to fly the country' indicate, in my opinion, that he was in hourly fear of arrest." "It seems a very feasible theory," remarked Wingate. "The rest is easy to understand. He nourishes a morbid hatred for the man who has been the means of menacing his liberty, and driving him from the society he polluted. He regards him as a personal enemy, not merely the instrument of the justice he has defied. While smarting under this, to his distorted ideas, sense of wrong, he pens the letter and has it conveyed to your father by some trusted confederate. As there is no stamp or postmark on it, it was conveyed by hand." Wingate looked at Sheila, and she returned his glance. They were both greatly impressed by the detective's clear reasoning. Smeaton took up the half-sheet of notepaper, and submitted it to a close observation. "The man who wrote it is, I should judge, a keen business man of methodical habits, inclined to neatness, of a strong but not impulsive character. An impulsive man would have torn the sheet across, leaving a rough and jagged edge. It has been pressed down with the finger and thumb, and then carefully cut." He held the small sheet up to the light, and made further observations. "A peculiar paper, peculiar, I mean, as to the texture. The watermark, in its entirety, is, fortunately for us, on this half-sheet. That enables us to trace where it comes from. Come here for a moment and stand beside me." They did so, followed his pointing finger, and saw a shield bearing a coat-of-arms, and beneath, the words: "Westford Mill."