In the Musgrave Ritual, there is a set of questions and answers that each generation of the Musgrave family had to memorize. This set of answers gave directions to a place, but it had been forgotten what it meant. Part of the directions included information about the shadows of trees. Holmes learned the height of a tree that had been cut down, and figured out where the shadow should have fallen. He went to the place, followed the directions, and found the hidden treasure. The only problem is, the height of the tree he had been given was from about twenty years previous to his adventure, while the questions and answers had been written over 200 years previous. If that was the case, the tree would have grown a great deal, making the directions useless.