“The same afternoon saw us both at Hurlstone. Possibly you have seen pictures and read descriptions of the famous old building, so I will confine my account of it to saying that it is built in the shape of an L, the long arm being the more modern portion, and the shorter the ancient nucleus from which the other has developed. Over the low, heavy-lintelled door, in the centre of this old part, is chiselled the date, 1607, but experts are agreed that the beams and stonework are really much older than this. The enormously thick walls and tiny windows of this part had in the last century driven the family into building the new wing, and the old one was used now as a storehouse and a cellar, when it was used at all. A splendid park with fine old timber surrounds the house, and the lake, to which my client, had referred, lay close to the avenue, about two hundred yards from the building.
“I was already firmly convinced, Watson, that there were not three separate mysteries here, but one only, and that if I could read the Musgrave Ritual aright I should hold in my hand the clue which would lead me to the truth concerning both the butler Brunton and the maid Howells. To that then I turned all my energies. Why should this servant be so anxious to master this old formula? Evidently because he saw something in it which had escaped all those generations of country squires, and from which he expected some personal advantage. What was it then, and how had it affected his fate?
“It was perfectly obvious to me, on reading the Ritual, that the measurements must refer to some spot to which the rest of the document alluded, and that if we could find that spot we should be in a fair way towards finding what the secret was which the old Musgraves had thought it necessary to embalm in so curious a fashion. There were two guides given us to start with, an oak and an elm. As to the oak there could be no question at all. Right in front of the house, upon the left-hand side of the drive, there stood a patriarch among oaks, one of the most magnificent trees that I have ever seen.
“‘That was there when your Ritual was drawn up,” said I as we drove past it.
“‘It was there at the Norman Conquest in all probability,” he answered. “It has a girth of twenty-three feet.”
“Here was one of my fixed points secured.
““Have you any old elms?” I asked.
“‘There used to be a very old one over yonder, but it was struck by lightning ten years ago, and we cut down the stump.”
“‘You can see where it used to be?”
““Oh, yes.”
“‘There are no other elms?”
““No old ones, but plenty of beeches.”
“‘I should like to see where it grew.”
“We had driven up in a dog-cart, and my client led me away at once, without our entering the house, to the scar on the lawn where the elm had stood. It was nearly midway between the oak and the house. My investigation seemed to be progressing.
“‘I suppose it is impossible to find out how high the elm was?” I asked.
“‘I can give you it at once. It was sixty-four feet.”
“‘How do you come to know it?” I asked in surprise.
““When my old tutor used to give me an exercise in trigonometry, it always took the shape of measuring heights. When I was a lad I worked out every tree and building in the estate.”
“This was an unexpected piece of luck. My data were coming more quickly than I could have reasonably hoped.
“‘Tell me,” I asked, ‘did your butler ever ask you such a question?”
“Reginald Musgrave looked at me in astonishment. “Now that you call it to my mind,” he answered, “Brunton did ask me about the height of the tree some months ago in connection with some little argument with the groom.”
“This was excellent news, Watson, for it showed me that I was on the right road. I looked up at the sun. It was low in the heavens, and I calculated that in less than an hour it would lie just above the topmost branches of the old oak. One condition mentioned in the Ritual would then be fulfilled. And the shadow of the elm must mean the farther end of the shadow, otherwise the trunk would have been chosen as the guide. I had, then, to find where the far end of the shadow would fall when the sun was just clear of the oak.”
“That must have been difficult, Holmes, when the elm was no longer there.”
“Well, at least I knew that if Brunton could do it, I could also. Besides, there was no real difficulty. I went with Musgrave to his study and whittled myself this peg, to which I tied this long string with a knot at each yard. Then I took two lengths of a fishing-rod, which came to just six feet, and I went back with my client to where the elm had been. The sun was just grazing the top of the oak. I fastened the rod on end, marked out the direction of the shadow, and measured it. It was nine feet in length.
“Of course the calculation now was a simple one. If a rod of six feet threw a shadow of nine, a tree of sixty-four feet would throw one of ninety-six, and the line of the one would of course be the line of the other. I measured out the distance, which brought me almost to the wall of the house, and I thrust a peg into the spot. You can imagine my exultation, Watson, when within two inches of my peg I saw a conical depression in the ground. I knew that it was the mark made by Brunton in his measurements, and that I was still upon his trail.
“From this starting-point I proceeded to step, having first taken the cardinal points by my pocket-compass. Ten steps with each foot took me along parallel with the wall of the house, and again I marked my spot with a peg. Then I carefully paced off five to the east and two to the south. It brought me to the very threshold of the old door. Two steps to the west meant now that I was to go two paces down the stone-flagged passage, and this was the place indicated by the Ritual.
“Never have I felt such a cold chill of disappointment, Watson. For a moment it seemed to me that there must be some radical mistake in my calculations. The setting sun shone full upon the passage floor, and I could see that the old, foot-worn gray stones with which it was paved were firmly cemented together, and had certainly not been moved for many a long year. Brunton had not been at work here. I tapped upon the floor, but it sounded the same all over, and there was no sign of any crack or crevice. But, fortunately, Musgrave, who had begun to appreciate the meaning of my proceedings, and who was now as excited as myself, took out his manuscript to check my calculations.
“‘And under,” he cried. ‘You have omitted the” and under. “‘
“I had thought that it meant that we were to dig, but now, of course, I saw at once that I was wrong. “There is a cellar under this then?” I cried.
“‘Yes, and as old as the house. Down here, through this door.”
“We went down a winding stone stair, and my companion, striking a match, lit a large lantern which stood on a barrel in the corner. In an instant it was obvious that we had at last come upon the true place, and that we had not been the only people to visit the spot recently.
“It had been used for the storage of wood, but the billets, which had evidently been littered over the floor, were now piled at the sides, so as to leave a clear space in the middle. In this space lay a large and heavy flagstone with a rusted iron ring in the centre to which a thick shepherd’s-check muffler was attached.
“‘By Jove!” cried my client. ‘That’s Brunton’s muffler. I have seen it on him and could swear to it. What has the villain been doing here?”
“At my suggestion a couple of the county police were summoned to be present, and I then endeavoured to raise the stone by pulling on the cravat. I could only move it slightly, and it was with the aid of one of the constables that I succeeded at last in carrying it to one side. A black hole yawned beneath into which we all peered, while Musgrave, kneeling at the side, pushed down the lantern.
“A small chamber about seven feet deep and four feet square lay open to us. At one side of this was a squat, brass-bound wooden