Superintendent Wilson never mentioned business to his wife when things were going well; but whenever his usually clear brain seemed to be working amiss, it was his way to unload on her all his trouble. Not that Mrs. Wilson had a powerful intellect—far from it. She was a comfortable, motherly woman, inclined to stoutness, and completely wrapped up in her children and her home. For her husband she had a profound admiration. He was, to her mind, not merely the finest detective in Europe, but the cleverest man in the world. But she was quite content to admire his cleverness without understanding it; and her husband made no attempt, as a rule, to discuss his cases with her.
He had found, however, that on the rare occasions on which his thinking got into a blind alley, her very passivity was the best possible help he could have. As he talked to her, and as she assented unquestioningly to everything that he said, new ideas somehow arose in his mind. Doubts were dispelled, new courses of action suggested, the weak spots in the armour of crime became apparent. He would tell her that she had been the source of his most brilliant inspirations; and she would placidly accept the role, without bothering to inquire in what way she contributed to his flashes of insight into the most abstruse mysteries that came under the notice of the Criminal Investigation Department.
It was a sign of deep dissatisfaction with the progress of the Brooklyn case that the superintendent now took his troubles home to his wife. He found her, in the pleasant sitting-room of their house facing Clapham Common, placidly knitting woollies for the children in anticipation of the coming winter. From the garden came the noise of the children themselves, playing a game which involved repeated shouts of “Bang, bang, bang!” as the rival armies engaged.
“My dear. I want to consult you,” he said, coming up and kissing her.
Mrs. Wilson laid down her knitting on the table beside her, and composed herself to listen.
“It’s about this Brooklyn case. I suppose you’ve read about it in the papers. I’m working on it, you know.”
Mrs. Wilson, who confined her newspaper reading to a glance at the pictures and headlines in the Daily Graphic, had barely heard of the case, and knew none of the details. Her husband therefore began by giving her a brief, but perfectly clear, account of the circumstances of the crimes. It helped to clear his own mind, and to put the essential facts in their proper focus.
“How dreadful!” was Mrs. Wilson’s appropriate comment at various points in the story. “And who did it?” she asked when her husband had done, smiling at him as if he were certain to know.
“My dear, if I knew that, I shouldn’t need to consult you. Blaikie feels quite certain it was Walter Brooklyn, old Sir Vernon’s brother. I’d better tell you just what there is against him.” And the superintendent gave an account of the evidence leading to the presumption of Walter Brooklyn’s guilt—the walking-stick, his failure to explain his movements on the night of the murders, his very strong motive for the crimes, and finally, the telephone message sent from Liskeard House on the fatal evening.
“But you say he didn’t do it. Then who did?” asked his wife.
“No, my dear, I didn’t say he didn’t do it. All I say is that I’m not satisfied that he did.”
“But you say he sent the telephone message—”
“Even if he did send the message, that doesn’t prove that he committed the murders. He may have been there, and yet someone else may be the murderer. But I’m not even sure that he ever did send the message.”
“If he didn’t send it, someone else did.”
“Yes, my dear, that’s the very point. But if it was someone else, then that someone was deliberately trying to incriminate Walter Brooklyn.”
“That is what you call laying a false clue, isn’t it?”
“Yes, but the trouble is that, if the telephone and the walking-stick are false clues, we have to deal with two quite different sets of false clues, both deliberately laid, and pointing to quite different conclusions as to the murderer. Is that possible?” The superintendent paused, and looked at his wife. But instead of answering, she got up and went to the window. “Georgie,” she said, “you mustn’t pull the cat’s tail. If you’re not good I shall send you to bed.” Then she came back to her seat. “Yes, dear, you were saying—”
“I was asking whether it was credible that someone should have laid two sets of quite inconsistent false clues for the purpose of misleading us.”
“Two sets of clues, dear. And both to mislead you. It must be very difficult to see through them both.”
“By George,” exclaimed the superintendent, leaping from his chair and beginning to pace up and down the room. “By George, you’ve given me just the idea I wanted. Yes, that must be it.”
“What must be what, dear? I had no idea I’d said anything clever.”
“Why, both sets of clues weren’t meant to mislead us. That’s it. The criminal laid two sets of false clues. He meant us to see through one set; but he thought we should never see through the other. He reckoned it would never occur to us that both sets of clues were false. Oh, yes. We were to feel awfully bucked up about seeing
