“I have a luncheon engagement in half an hour, and can give you twenty minutes, but it will do no good, I am sure. Won't you sit down?” and Mr. Harlow placed a chair for her near his desk. “Thank you,” said Mary, as she seated herself, “I will be as brief as possible. I have read of many murder cases, but I believe I never knew of one in which there was more conclusive evidence against the person accused than in this instance. When I first took up the case, my father did not think there was a possible loophole of escape for him; but the truth does not always appear on the surface. Then, jurors get wrong impressions. Witnesses are often prejudiced. Sometimes the judge is not impartial. Then there are coincidences which are fatal so far as appearances go, but which can be satisfactorily explained.” The district attorney nodded, somewhat impatiently, and fingered his watch-chain. “The day after the murder I called on Mabel Ellicott, primarily to ask her some questions about Robert Wood, but I also had a chance to see the body of her father, and to examine the wound upon the murdered man's head. I decided that Mr. Ellicott had been struck with something else beside the oaken staff which, covered with blood, was found near his chair. In fact, I found in the wound certain foreign substances which could not have formed part of an oaken staff. “That was a clue, but I told it only to my father and Mr. Sawyer. It led us to look for something else. I must confess that a week passed without our discovering anything to bolster up my opinion. Finally, it occurred to me that perhaps the foreign substances I had found in the wound might have been on that part of the cane that comes in contact with the ground. But we will drop that for the present. “Back of the mill is a piece of sunken ground. During the night, after Mr. Ellicott was murdered, there was a heavy fall of rain, and this piece of sunken ground was covered with water to the depth of several inches, in some places, at least six. I do not mean that the rainfall was so great, but the water ran down from higher elevations until it made, what appeared to be, quite an extensive pond. “Mr. Sawyer and I made several circuits of this temporary pond; why, I could not exactly tell you. A detective, I have been told, can seldom tell why he examines certain objects so closely, but something seemed to draw me towards that improvised lake. “While looking at the water, I saw something which projected several inches above its surface, and I had a curiosity to know what it was. Mr. Sawyer put on a pair of rubber boots, and waded out to it, lifted it from the water, and found it to be a large, irregular shaped stone weighing at least ten pounds, which he brought back to me. He then went back and splashed round in the pond with the hope of finding something else of interest, but could discover nothing.