“Now consider the situation as he considered it. On Sunday night in the library, when Graham was blackmailing Harrison, Anita came in and quarreled with her father about Allen. There he had one person, two in fact, with a motive for murder. Allen’s room was handy to the Japanese bow. Graham’s one mistake was not making sure that the Japanese bow would shoot that hard.”
“You’re mad!” shouted Graham suddenly. Studying him for an instant, Landis saw signs that he was cracking under the strain. Bernard drove smoothly on with his indictment.
“There were other people with possible motives, too. Joel was little more than a half-wit, could shoot well and was mercilessly bullied by his brother. Again, Graham may have overheard enough to know that Russell was sore on Harrison for not letting him marry Isabelle unless and until he went to work. Russell was handy to the Japanese bow also.
“Of course Graham watched Harrison closely, noticed that he stooped when he went through a door and above all, noticed the regularity of his habits in the evening. The household was run like clockwork. So Graham could be sure exactly where most of the inmates would be at the time he planned to kill Harrison. On his visit to Joel’s den, which he could reach only through Miss Mount’s room, he looked out her window and saw a clear path to the reception-room door. Now the really brilliant method came to him. For it permitted him to shoot Harrison from close to his own room and also to work out an alibi that looked perfect—but wasn’t!”
“The bath water running!” Landis exclaimed.
“Exactly! To go back a little, before he murdered Harrison he had another idea. Perhaps Miss Mount would do it for him! So he deliberately burned his wife’s back with his cigarette, close to the scar. Miss Mount heard her scream and came across the hall as he hoped. He left her to find the scar. He knew that she questioned his wife next morning and then was gone all day. He knew, no doubt, that his wife had given her the address of the Cuddys as she told us she had. It was easy to guess that Miss Mount had gone to see them and would learn what he had learned. Her quarrel with Harrison that night satisfied him that she had learned, for the first time, the trick Harrison had played on her.
“So far so good. Graham waited to see whether Miss Mount would do his work for him. But she limited herself to making a fuss of Ethel. So he went ahead with his own plans, content to know that in Miss Mount he had an alternative suspect with an especially strong motive. That’s why he told us as much as he did about Ethel and let us guess that Miss Mount was her mother. He led us up to that very cleverly!
“Now for what actually happened. The night before the murder, Friday night, he got the cross-bow and the gloves from Joel’s room and hid them in his own. During the night he put on the gloves, stole down to the library, detached the Japanese bow from the armor, strung it and left it leaning handy there. He took back with him an unblunted Japanese arrow and hid that in his room as well.
“Saturday night, when they all came home to dress, he delayed his wife and himself by romping with her. Giving their lateness as an excuse, he rang for Helen to help her dress. He wanted Helen as an additional witness to his alibi.
“He went into the bathroom, probably locked the door into his wife’s room and turned on the bathwater. Then he stripped, resumed his coat and trousers and wound up the cross-bow, wiping it clean of finger-prints afterwards.