“Yes, as you will see, even had I discovered some other opening, secret or otherwise, it would not have helped at all to explain the mystery of the incredible attack, in a normal fashion.  For the butler, as you know, was struck in full sight of the Rector, Sir Jarnock and his son.  And old Bellett himself knew that no living person had touched him.... ’Out of the Void,’ the Rector had described the inhumanly brutal attack.  ’Out of the Void!’ A strange feeling it gives one—­eh?

“And this is the thing that I had been called in to bottom!

“After considerable thought, I decided on a plan of action.  I proposed to Sir Alfred Jarnock that I should spend a night in the Chapel, and keep a constant watch upon the dagger.  But to this, the old knight—­a little, wizened, nervous man—­would not listen for a moment.  He, at least, I felt assured had no doubt of the reality of some dangerous supernatural Force a roam at night in the Chapel.  He informed me that it had been his habit every evening to lock the Chapel door, so that no one might foolishly or heedlessly run the risk of any peril that it might hold at night, and that he could not allow me to attempt such a thing after what had happened to the butler.

“I could see that Sir Alfred Jarnock was very much in earnest, and would evidently have held himself to blame had he allowed me to make the experiment and any harm come to me; so I said nothing in argument; and presently, pleading the fatigue of his years and health, he said goodnight, and left me; having given me the impression of being a polite but rather superstitious, old gentleman.

“That night, however, whilst I was undressing, I saw how I might achieve the thing I wished, and be able to enter the Chapel after dark, without making Sir Alfred Jarnock nervous.  On the morrow, when I borrowed the key, I would take an impression, and have a duplicate made.  Then, with my private key, I could do just what I liked.

“In the morning I carried out my idea.  I borrowed the key, as I wanted to take a photograph of the chancel by daylight.  When I had done this I locked up the Chapel and handed the key to Sir Alfred Jarnock, having first taken an impression in soap.  I had brought out the exposed plate—­in its slide—­with me; but the camera I had left exactly as it was, as I wanted to take a second photograph of the chancel that night, from the same position.

“I took the dark slide into Burtontree, also the cake of soap with the impress.  The soap I left with the local ironmonger, who was something of a locksmith and promised to let me have my duplicate, finished, if I would call in two hours.  This I did, having in the meanwhile found out a photographer where I developed the plate, and left it to dry, telling him I would call next day.  At the end of the two hours I went for my key and found it ready, much to my satisfaction.  Then I returned to the castle.

“After dinner that evening, I played billiards with young Jarnock for a couple of hours.  Then I had a cup of coffee and went off to my room, telling him I was feeling awfully tired.  He nodded and told me he felt the same way.  I was glad, for I wanted the house to settle as soon as possible.