"Now, witness," said Mr. Walters, suddenly changing his tone to one of more severity than he had previously used, "you have told us that you heard Sir Horace Fewbanks and the prisoner in the library while you stood in the wood by the garage, and that subsequently you saw Sir Horace leaning out of the window after the prisoner had gone. You are quite sure you were able to see and hear all this from where you stood?" "Yes." "Are you aware, witness, that there is a large chestnut-tree at the side of the library, in front of the window?" Kemp considered for a moment. "Yes," he said. "And did not that tree obstruct your view of the library window?" "No." "Witness," said Mr. Walters solemnly, "listen to me. This tree did not obstruct your view when you went to Riversbrook a week or so ago to decide on the nature of the evidence you would give in this court. It is bare of leaves now, and you could see the library window and even see into the library from where you stood. But I put it to you that on the 18th of August, when this tree was covered with its summer foliage, you could no more have seen the library window behind its branches than you could have seen the inhabitants of Mars. What answer have you got to that, witness?" There was a slight stir in court--an expression of the feeling of tension among the spectators. Kemp drew the back of his hand across his lips, then moistened his lips with his tongue. "Come, witness, give me an answer," thundered prosecuting Counsel. "I tell you I saw him after Mr. Holymead had left," declared Kemp defiantly. His voice had suddenly become hoarse. To the surprise of the members of the legal profession who were in court, Mr. Walters, instead of pressing home his advantage, switched off to something else. "I believe you have a feeling of gratitude towards the prisoner?" he asked, in a milder tone. "I have," said Kemp. His defiant, insolent attitude had suddenly vanished, and he gave the impression of a man who feared that every question contained a trap. "He did something for a relative of yours which at that time greatly relieved your mind?" "He did, and I'll never forget it." "Well, we won't go further into that at present. But it is a fact that you would like to do him a good turn?" "Yes." "You came here with the intention of doing him a good turn?" Kemp considered for a moment before answering: "Yes." "You came here with the intention of giving evidence that would get him off?" "Yes." "You came here with the intention of committing perjury in order to get him off?" Mr. Walters waited, but there was no reply to the question, and he added, "You see what your perjured evidence has done for him?" "What has it done?" asked Kemp sullenly.