Having thus decided, Walter Dene proceeded to lay his plans with deliberate caution. He had no intention whatsoever of being detected, though his method of action was simplicity itself. It was only bunglers and clumsy fools who got caught; he knew that a man of his intelligence and ability would not make such an idiot of himself as--well, as common ruffians always do. He took his old American bowie-knife, bought years ago as a curiosity, out of the drawer where it had lain so long. It was very rusty, but it would be safer to sharpen it privately on his own hone and strop than to go asking for a new knife at a shop for the express purpose of enabling the shopman afterwards to identify him. He sharpened it for safety's sake during sermon-hour in the library, with the door locked as usual. It took a long time to get off all the rust, and his arm got quickly tired. One morning as he was polishing away at it, he was stopped for a moment by a butterfly which flapped and fluttered against the dulled window-panes. "Poor thing," he said to himself, "it will beat its feathery wings to pieces in its struggles;" and he put a vase of Venetian glass on top of it, lifted the sash carefully, and let the creature fly away outside in the broad sunshine. At the same moment the vicar, who was strolling with his King Charlie on the lawn, came up and looked in at the window. He could not have seen in before, because of the dulled and painted diamonds. "That's a murderous-looking weapon, Wally," he said, with a smile, as his glance fell upon the bowie and hone. "What do you use it for?" "Oh, it's an American bowie," Walter answered carelessly. "I bought it long ago for a curiosity, and now I'm sharpening it up to help me in carving that block of walnut wood." And he ran his finger lightly along the edge of the blade to test its keenness. What a lucky thing that it was the vicar himself, and not the gardener! If he had been caught by anybody else the fact would have been fatal evidence after all was over. "Mefiez-vous des papillons," he hummed to himself, after Beranger, as he shut down the window. "One more butterfly, and I must give up the game as useless." Meanwhile, as Walter meant to make a clean job of it--hacking and hewing clumsily was repulsive to all his finer feelings--he began also to study carefully the anatomy of the human back. He took down all the books on the subject in the library, and by their aid discovered exactly under which ribs the heart lay. A little observation of the vicar, compared with the plates in Quain's "Anatomy," showed him precisely at what point in his clerical coat the most vulnerable interstice was situated. "It's a horrid thing to have to do," he thought over and over again as he planned it, "but it's the only way to secure Christina's happiness." And so, by a certain bright Friday evening in August, Walter Dene had fully completed all his preparations.