"'Why not sugar?' said Mr. Barnes.
"'I don't know. That never occurred to me. Perhaps it was. At all events I have not had a drop of anything since, except water. No tea, no coffee, no liquor that might hide a poison. Only clear water, drawn from the hydrant with my own hands, into a cup that I carried about my person, and washed out before every draught. I was determined that he should not poison me except by poisoning the reservoir. This necessitated adopting a plan for eating that would be equally safe. So I have taken to eating at restaurants, a different one for every meal.'
"'You have allowed yourself to become morbid on this subject. I should not be surprised if this man really has no intention of committing this murder, but has taken this means of having revenge, by causing you a month of mental suffering.'
"'I hardly think that. He has made several efforts to kill me already.'
"'In what manner?'
"'Well, twice, in my own house, I was shot at from without. I heard the report of a pistol each time, and a ball passed close to me and entered the wall at my side. After the second attempt I decided to change my place of abode, and took a room at my club. The room had but one window, and that opened on the interior court. I was particular that it should not be exposed to the street. For several days nothing happened; then one night, just as I was putting out my gas, and consequently standing by the window, again I heard a pistol shot, and another bullet whistled past me, all too close. The odd thing was that though I had an immediate investigation made, it is certain that my enemy was not in the building.'
"'In that case, the shot must have come in accidentally. Some one opposite was probably handling his pistol and carelessly touched the trigger, causing the explosion. Naturally, when he found that you had nearly been shot, he chose not to make any explanations.'
"'However that may be, I thought it best to move again. This time I found a room in a hotel, where the only ventilation is from a skylight opening upon the roof. In there at least I have felt safe from intruding bullets. But I am disturbed by the regularity with which those postal-cards come to me. The address has always been changed as I have moved from one place to another.'
"'Evidently your man keeps an eye upon you.'
"'Very evidently, though I have never set eyes upon him since his visit on the night when he made me give him that diabolically conceived promissory note. Now that is the story. Can you do anything for me?'