“For some minutes further I watched it, lifting it out once or twice to make a more exact scrutiny, but could not imagine what the markings might represent, until suddenly it occurred to me that in one of two places they certainly had shapes suggestive of a cross hilted dagger.  Yet, the shapes were sufficiently indefinite to make me careful not to let myself be overimpressed by the uncomfortable resemblance, though I must confess, the very thought was sufficient to set some odd thrills adrift in me.

“I carried development a little further, then put the negative into the hypo, and commenced work upon the other plate.  This came up nicely, and very soon I had a really decent negative that appeared similar in every respect (except for the difference of lighting) to the negative I had taken during the previous day.  I fixed the plate, then having washed both it and the ‘unexposed’ one for a few minutes under the tap, I put them into methylated spirits for fifteen minutes, after which I carried them into the photographer’s kitchen and dried them in the oven.

“Whilst the two plates were drying the photographer and I made an enlargement from the negative I had taken by daylight.  Then we did the same with the two that I had just developed, washing them as quickly as possible, for I was not troubling about the permanency of the prints, and drying them with spirits.

“When this was done I took them to the window and made a thorough examination, commencing with the one that appeared to show shadowy daggers in several places.  Yet, though it was now enlarged, I was still unable to feel convinced that the marks truly represented anything abnormal; and because of this, I put it on one side, determined not to let my imagination play too large a part in constructing weapons out of the indefinite outlines.

“I took up the two other enlargements, both of the chancel, as you will remember, and commenced to compare them.  For some minutes I examined them without being able to distinguish any difference in the scene they portrayed, and then abruptly, I saw something in which they varied.  In the second enlargement—­the one made from the flashlight negative—­the dagger was not in its sheath.  Yet, I had felt sure it was there but a few minutes before I took the photograph.

“After this discovery I began to compare the two enlargements in a very different manner from my previous scrutiny.  I borrowed a pair of calipers from the photographer and with these I carried out a most methodical and exact comparison of the details shown in the two photographs.

“Suddenly I came upon something that set me all tingling with excitement.  I threw the calipers down, paid the photographer, and walked out through the shop into the street.  The three enlargements I took with me, making them into a roll as I went.  At the corner of the street I had the luck to get a cab and was soon back at the castle.

“I hurried up to my room and put the photographs way; then I went down to see whether I could find Sir Alfred Jarnock; but Mr. George Jarnock, who met me, told me that his father was too unwell to rise and would prefer that no one entered the Chapel unless he were about.