Presently he sat up.
“Of course you will want an explanation, and you are entitled to one. It will help pass the time.”
“If you are too tired we can wait,” said Mabel, but she was on the rack. Her brother, the man who had been her lover, and he who had lately filled so much of her life and whom she had grown to respect even if there was no deeper feeling, were all involved.
Sinclair started like a tired man, but as he went on he warmed to his tale.
“Collins was a deep scoundrel, but like all such he had two weaknesses. He was so vain that he could not leave things alone, he must try daring experiments, and he regarded all mankind as fools. That was where he made his great mistake. I don’t expect we shall ever know the truth, for I am certain he will never be taken alive.
“A great amount is still obscure, in fact, it was only this evening that I was sure I was right. Otherwise, of course, I should have acted before. The first indication I had was a very slight slip, so slight that it was almost instinct that made me notice it. He was recounting Mrs. Simmons’ evidence to Boyce and myself, and he said that she had stated that Sir James had complained of feeling sleepy. Now I was sure that she had said nothing of the sort, and I took the trouble to ask her after, and she was certain he had never said so. In a curious way this kept on recurring to my mind, but I dismissed it. Mind you, I hadn’t the remotest suspicion at the time. I merely thought it curious.
“Then, of course, I had a letter from Sir James the day after the murder.”
The other two looked at him in surprise.
“Oh, of course, you don’t know about that.” He felt in his pocket and produced the letter, which he read to them.
“Again I was struck with the fact that he had been anxious not to have Collins told. It stuck in my mind, until recalled, in a vivid manner. I was in his flat, and we were discussing the evidence of Mrs. Simmons, when he suddenly said he heard a noise, and went to the door, dramatically taking his pistol with him.