"Not at all, sir, not at all," exclaimed Thornton heartily. "I am most anxious to have this terrible affair cleared up as soon as possible. Simply state your wishes and they will be carried out to the best of my ability." "Thanks." The coroner seated himself at the mahogany table standing in the center of the room and drew out his notebook and fountain pen, while Brett established himself on the opposite side. "Shall I retire?" inquired the Colonel. "I think it would be best," replied Dr. Penfield gravely. "I prefer to examine the members of the household separately. No offense is intended." "And none is taken." Thornton smiled wearily. "You forget I'm a lawyer, Doctor, and understand your position. If you wish to see me I will be in my room." "All right, Colonel." The coroner consulted his notebook as Thornton left them, then turned to Douglas. "You were the first to enter the southwest chamber, were you not?" "Yes, I broke in a panel of the door with Colonel Thornton's assistance, and----" "One moment." Penfield held up his hand. "Was the door locked on the _inside_?" "Yes, by an old-fashioned bolt, as well as by lock and key." "Did the bolt and lock work stiffly?" "They did." "In your opinion would a person locking the door and shooting the bolt into place make enough noise to awaken the sleeper?" "I think so, yes." "Did you find the windows of the room also bolted when you entered?" "No, they were closed, but the bolts, similar to the one on the door, only smaller, were not fastened." "I see." Penfield drummed on the table for a moment with his left hand. "Could anyone have slipped past you and Colonel Thornton when you stood waiting in the hallway for the gas to evaporate?" "No, we would have been sure to see them, and, besides, no one could have remained in that room alive, the escaping gas was overpowering." "Did the room have no other exit except the one door leading to the hall?" "That is all I could discover. I searched the room thoroughly with Brett." The detective nodded affirmatively. "We could find no trace of any other entrance or exit." "Strange!" exclaimed Penfield. "The windows are too great a height from the ground, and can only be reached by a scaling ladder." "And beside that," put in Brett, "I've examined the ground under and near the two windows of that room, and there isn't a trace of a footstep or ladder anywhere around." The coroner laid down his pen. "I think that is all just now, Mr. Hunter. Brett, will you ask Dr. Marsh to step here." The two men left the room. "I'll wait in the drawing-room, Brett," called Douglas, as the detective started upstairs to find the doctor. In a few minutes Brett reappeared in the library with Dr. Marsh. "I won't detain you long, doctor," began Penfield. "Be seated. You were the first to examine the dead woman upstairs; what do you think caused her death?"