To the ordinary listener O'Sullivan's story would have seemed of little or no importance. Not so, however, with Schuettler and Wing. These experienced officials, who knew of old that important results often follow in the wake of the most unpromising trail, saw in it a possible clue. Together they drove with all haste to the Carlson cottage. It was broad daylight, and even before they had alighted from their buggy, they saw enough to convince them that they were on the right track at last. There were big blood stains on the boards, that crossed the ditch in front of the gate. There were larger ones on the sidewalk in front of the house; and they led, in two dark-red parallel streams right up the wooden steps to the front door. It was the work of a couple of seconds to force the lock. The usually cool, imperturbable officials were too excited to go after keys, while, moreover, it was desirable that what was to be done should be done quietly. The lock gave way to the pressure with a crash, and the two men entered. Spots of blood again confronted them on the floor of the hall. An attempt had been made to cover some of them up with a coat of yellow paint. The individual who performed this task had divested himself of his boots and hose, for the print of a naked foot stood out clear and distinct in a splotch of the red paint. [Illustration: A FOOTPRINT IN THE HALL.] A couple of steps and the captains were in the parlor, and then for the first time they realized the full and terrible import of their discovery. There were abundant evidences that a frightful struggle for life had taken place within the four walls, and that it was here that the unfortunate physician had met his doom. It was a small room, only 16 by 20 feet, with three windows, two facing west on Ashland Avenue and a third looking out south on a vacant lot. Near the southwest corner was a bloody stain nearly a foot in diameter and about four feet away from the wall. Almost in the center of the room was another blood-stain almost as large. It looked as though a body had been rolled from one place to the other, the changes of position leaving a small pool wherever the head had rested. Over these stains the same reddish brown paint that appeared in the hallway had been applied, but in such a bungling way as to leave no doubt that it had been done with great haste. The stains of blood were not heavy, and it was apparent that the life-fluid had soaked through a carpet before reaching the wood. In the northeast corner was a bedstead, in the northwest a dressing-case, in the southeast a wash-stand with a pitcher and bowl. In the center of the room was a rocking-chair. The right arm was broken off and lay on the floor, and the officials came quickly to the conclusion that the physician was sitting in this chair when he was first attacked. [Illustration]