After sending for Dr. Brandt and his colleague, the two police captains lost no time in putting the Carlsons on the rack. It was evident from the start that the family had known all about the condition of the interior of the cottage for days, if not weeks. They had hesitated about notifying the police, however, for fear that difficulty would be experienced in renting the cottage if the facts became known; while, at the same time, they were afraid to destroy and efface the evidences of the crime that they realized had been committed. Mrs. Carlson did not need any pressing to tell what she knew. From her story it was developed that on March 20th a tall, slender, pale-faced young man called at her house to learn the rent of the cottage. He was told he could have it for $12 monthly. The amount suited him, and he paid a month's rent in advance, without being requested to do so, and received the key. He went on to say that his name was Frank Williams, that he had two brothers and a sister, who would live with him, and that the sister would keep house. They were coming from Baltimore, and would join him in a day or two. He took the keys and went away, but the sister never came. [Illustration: THREE OF THE CARLSON FAMILY.] For a month there were no outward signs that the mysterious Frank Williams intended to occupy the building he had rented. Mrs. Carlson became very uneasy. Nearly seven weeks prior to the disappearance of the physician, or to be precise, on Wednesday, March 20th, just about the noon hour, a man of medium size, with dark hair and eyes, a full mustache, a derby hat, pulled well down over his forehead, and a heavy overcoat buttoned up around him, had knocked at the door of the little cottage occupied by the Carlsons. Mrs. Carlson herself was absent at the time, but her husband, Jonas, Charles, their son, and the latter's wife, Annie, were at home at the time. The latter was a domestic servant in the employ of a prominent family on Michigan avenue; but--by another peculiar coincidence--this happened to be her "day off," the first she had taken for several weeks. Jonas Carlson answered the door, and the stranger inquired if he (Carlson) was the owner of the cottage on the front lot. Receiving an answer in the affirmative, he expressed a desire to rent it. Carlson secured the keys, and the two men went down to the cottage, entering by the rear door. The would-be tenant gave a cursory glance over the interior, and, remarking that there were six rooms, just the number that he required, asked what the rent would be. Carlson named the sum of twelve dollars monthly, to be paid in advance, but the stranger demurred and expressed the opinion that eleven dollars was quite enough. Finding, however, that Carlson was unwilling to lower his figure a single dime, the man at last remarked: "All right, I'll take it and give you the money now." The landlord and his new tenant then returned to the