Meantime, the detectives began their serious work. They proceeded with system and upon their own plan. They omitted to question not the least of the persons who dwelt at Chadlands, and inquired also privately concerning every member of the house party there assembled when Tom May died. Into the sailor's private life they also searched, and so gradually investigated every possible line of action and point of approach to his death. The cause of this they were content to disregard, arguing that if an assassin could be traced, his means of murder would then be learned; but, from the first, no sort of light illumined their activities, and nothing to be regarded as a clue could be discovered, either in Tom May's relations with the world, or in the history and character of anyone among the many who were subject for inquiry. Concerning the house party, only Ernest Travers and his wife had met the sailor before, on the occasion of his wedding; while as to the staff at Chadlands, nothing transpired to indicate that any had ever had occasion to feel affronted by an act of his. They were, moreover, loyal to a man and woman. They furnished no peculiarities, and gave no ground for the least suspicion. The case, in Frith's opinion, was unique, because, despite the number of persons it was necessary to study and consider, in none of their relations with the family involved could there be found a shadow of unfriendly intercourse, a harbored grudge, or a suggestion of ill-feeling. The people were all simple and ingenuous. They declared and displayed nothing but regard for their employer, and many of them had succeeded their own parents in their present employment. It was a large household, very closely united by ties of tradition and affection. Henry Lennox also proved above suspicion, though his former attachment to Mary was not concealed. It needed no great student of character, however, to appreciate his transparent honesty under examination, a remark that extended to Dr. Mannering, whose incautious advent in the corridor on the night of their vigil had offended the watchers. For three weeks they worked industriously--without vision, but to the best of their experience and intellectual powers. In the familiar phrase, they left no stone unturned; and following their report, which frankly admitted absolute failure, a small commission instituted a further inquiry on the evidence, and invited those chiefly concerned to attend it. Sir Walter, his daughter, Henry Lennox, and Dr. Mannering were examined with sympathy and consideration. But they could offer no opinions, throw no light, and suggest no other lines of inquiry than those already pursued.