If it hadn't been for the fact that Preston was in California at the time, working on the case of a company that was using the mails for illegal purposes, it is extremely doubtful if the mystery would ever have been solved [Quinn continued]; certainly not in time to prevent the escape of the criminal. But Hal's investigations took him well up into the foot-hills of the Sierra Nevadas, and one morning he awoke to find the whole town in which he was stopping ablaze with a discussion of the "Montgomery mystery," as they called it. It appeared from the details which Preston picked up in the lobby of his hotel that Marshall Montgomery had settled down in that section of the country some three years before, but that he had surrounded himself with an air of aloofness and detachment which had made him none too popular. Men who had called to see him on matters of business had left smarting under the sting of an ill-concealed snub, while it was as much as a book agent's life was worth to try to gain entrance to the house. "It wasn't that he was stingy or close-fisted," explained one of the men who had known Montgomery. "He bought more Liberty Bonds than anyone else in town--but he bought them through his bank. Mailed the order in, just as he did with his contributions to the Red Cross and the other charitable organizations. Wouldn't see one of the people who went out to his place. In fact, they couldn't get past the six or eight bulldogs that guard the house." "And yet," said Preston, "I understand that in spite of his precautions he was killed last night?" "Nobody knows just when he was killed," replied the native, "or how. That's the big question. When his servant, a Filipino whom he brought with him, went to wake him up this morning he found Montgomery's door locked. That in itself was nothing unusual--for every door and window in the place was securely barred before nine o'clock in the evening. But when Tino, the servant, had rapped several times without receiving any reply, he figured something must be wrong. So he got a stepladder, propped it up against the side of the house, and looked in through the window. What he saw caused him to send in a hurry call for the police." "Well," snapped Preston, "what did he see?" "Montgomery, stretched out on the floor near the door, stone dead--with a pool of blood that had formed from a wound in his hand!" "In his hand?" Preston echoed. "Had he bled to death?" "Apparently not--but that's where the queer angle to the case comes in. The door was locked from the inside--not only locked, but bolted, so there was no possibility of anyone having entered the room. The windows were tightly guarded by a patented burglar-proof device which permitted them to be open about three inches from the bottom, but prevented their being raised from the outside." "Was there a chimney or any other possible entrance to the room?"