"No, it isn't," he said.
"I beg your pardon?"
"It isn't. I didn't say it was the explanation; I only said those were inferences to be drawn from the hypothesis that Depping put out his own lights. And I wish it were as simple as that. But let's proceed for a moment on that assumption, and see. what we find.
"H’m. Harrumph. There is a very, very grave objection to this theory. If Depping wished to entertain a secret visitor, why did he indulge in all that elaborate and dangerous mummery? Why go to all the trouble of putting a loud check suit and a false moustache on his visitor, dousing the lights, and mysteriously bringing him in at the front door? Why not simply bring him up to the balcony, and through the balcony door unknown to anybody? Why not smuggle him in at the back door? Why not bring him through a window, if necessary? Why not adopt the simplest course of all: send the servants to bed and let him in himself — front door, balcony door, or back door?
"You see, that theory won't work. Nobody but a lunatic would have arranged a meeting like that. There must have been a very good reason why it was done in that way."
He paused for a long time.
To see whether we can explain it, remember that the balcony door, which is always kept locked, was found open this morning. Not only was this door usually locked, but the key was not in it at all; it hung on a nail in a pantry downstairs. And it is gone now. Who took that key, and who opened the door? The murderer left that way, and it must have been unlocked either by Depping or by the murderer. Keep that fact fixed in your mind while we consider the problem.
"Whoever the visitor was, or why he was admitted under such circumstances of hocus-pocus, look at the facts and see what happened afterwards. Depping and X are closeted together, amiably enough to all purposes, and some very extraordinary things occur. They are seen by the cook putting up all the windows in the midst of a blowing thunderstorm… What does that suggest to you?"
The bishop was pacing about at a measured and thoughtful gait.
"I can scarcely imagine," he replied, "that they did so because they wanted to air the room."