“Sit down again,” said Crewe kindly. “Do not excite yourself. You and I can discuss this thing quietly whatever else is to happen afterwards.”
“How long have you known that I did it?” asked Marsland, after a pause.
“It was not until yesterday that I felt quite certain. What annoys me—what offends my personal pride—is that my impetuous young friend Gillett picked you out as the right man before I did. He was wrong in his facts, wrong in his deductions, wrong in his theories, and hopelessly wrong in his reconstruction of the crime. He had no more chance of proving a case against you than against the first man he might pick out blindfolded from a crowd, and yet he was right. True, he came to the conclusion that he was wrong when I put him right as to the circumstances under which the tragedy occurred, but that doesn’t soothe my pride altogether. If there is one lesson I have learned from this case, it is that humility is a virtue that becomes us all.
“But, after all, I do not think I have been so very long in solving the problem,” the detective continued. “It is only thirteen days since the tragedy took place, and from the first I saw it was a complicated case. I never ruled out the possibility of your being the right man after Brett and Miss Maynard tried to sheet home Lumsden’s death to you. I do not think she was fully in Brett’s confidence—in fact, it is fairly obvious that he would not tell her the story of his treachery. But he knew that you had shot Lumsden and she caught at his conviction without being fully convinced herself. Brett’s conduct was inconsistent with guilt. But it was consistent with the knowledge that Lumsden had met his death at your hands and that he himself would share the same fate if you encountered him.
“I am under the impression that he reached Lumsden a few minutes after you rode away from the spot, and that Lumsden was then alive. Probably he was able to breathe out your name to Brett. The latter helped the dying man into the motor-car and started to drive back to Staveley for medical aid, and after passing the thatched cottage on the right he became aware that Lumsden had collapsed and was past human aid. So he decided to take the body to the farm, and in order to disappear, without drawing immediate suspicion on himself, he tried to indicate that Lumsden was shot in the house.
“Then he disappeared because he was afraid of you. If he had got you under lock and key he might have risked coming into the open and giving evidence against you. But I rather fancy that his intention was to get away to a foreign country with old Lumsden’s money, and then put the police on your track by giving the true circumstances under which Lumsden was shot.”
“Did he write to you?” asked Marsland.
“No.”
“I was always afraid he would. What put you on my track?”
“The conviction that you had warned this girl to clear out as Gillett had obtained some awkward facts against her. You were the only person who had any object in warning her, though Gillett thinks you had even less reason to do so than Brett. I regarded you merely as an average human being and not actuated by Quixotic impulses. I remembered that she had tried to sheet home the crime to you and therefore you had little cause to be grateful to her—so far I am in accord with Gillett. But if you knew that she had nothing to do with the tragedy, and if you felt that Gillett’s close questioning might lead to information from Brett which would tell against you, it was common sense on your part to get her out of the way.”