“I am not prepared to state that, but--I have made a discovery!” CHAPTER XVII. A THEORY FOUND. The discovery Nick Carter made was this: Where the body had been lying in the room, it had been surrounded by a pool of blood. But, when being dragged across the floor toward the door there had been no dropping of the sanguineous fluid. Then, after crossing the sill, the blood drops became visible and continued irregularly until this spot was reached, where there was quite a good-sized pool! About this there was certainly something crooked. Blood would not flow plentifully one minute, cease the next, and flow again in that following. What did he deduce from this? The deduction was that these blood spots were not the result of the wound that had been inflicted on Mr. Field. In other words they were placed there. The purpose for doing so remained for Nick to discover. The detective followed the tracks in the carpet along the hall. They were not once missing, in fact it seemed as though they had purposely been made very noticeable so that they might be readily followed. Co-existing with the depressions in the carpet were the spots of blood. Without once turning aside they led to the top of the back stairs and down those to the floor below. Through the lower hall they went to the rear door and out of this into the grounds. From the back door was a straight path that led away in the direction of the river. Down this path the traces were to be seen. Pausing in the doorway, the detective said: “I want you to answer me a few questions.” Barnes returned: “Go ahead. Call on me for any information that I can give.” “Has anybody yet followed these tracks here?” “Yes.” “Who?” “I did.” “Ah! How far did you go?” “Halfway down the grounds.” “I suppose, then, that you succeeded in mixing up your tracks with those of the men who had Mr. Field with them?” “I did not do that. I fancy that even though I am not a detective I am not wanting in common sense.” “How did you avoid doing so?” “By walking outside of the path. I thought that in all probability that you would want to examine the tracks, and so did all I could to see that they were kept distinct. I have kept the servants from coming here when they were desirous of doing so.” “You did well. Few people show as much sense, but usually appear to do all they can to make it difficult, if not impossible, for a detective to get hold of a clew.” As he said this Nick Carter was moving slowly down the path, taking care not to step upon or in any way obliterate whatever marks may have been there. The grounds extended toward the river a distance of six or seven hundred feet, in fact nearly to the railroad tracks. For half this distance the blood drops were visible and then they ceased.