"What do you mean?" said Mollie. Her face was very white--white as death. "What do you mean?"
"I happened to go into the sick-room the morning after Aylmer's death. Now listen--listen hard. Aylmer was ordered two medicines: one was what they call an alterative, or fever mixture--you know the kind?"
"Aylmer was to take two tablespoonfuls of the alterative medicine every two hours. He suffered intense pain from some obscure internal inflammation, and a sedative, which contained a large quantity of opium, was also to be given at stated intervals--a teaspoonful at a time. Those were the two medicines. When I went into Aylmer's room on the following morning, I found that Keith had given Aylmer the wrong medicine--he _said_ by mistake. Anyhow, Aylmer had taken two tablespoonfuls of the sedative and one teaspoonful of the fever mixture. The consequence was that he died. You must admit that a very ugly finger of suspicion points to Captain Keith, more particularly as I found out, after careful inquiries, that he wanted that ten thousand pounds badly just then."
"I don't think; I know. I have more to say. Keith was very ill after Aylmer's death--shock the doctors called it; but I, having made my discovery, knew better. I carried the bottles away with me. I have them still. When Keith was a little better I went to see him, and told him what had happened. I invited him to take the matter up and make inquiries; but he preferred to hush the whole thing into oblivion."
"My part is of no consequence. Had I been less soft-hearted, I should have gone straight to the coroner and told him what I had discovered. But I could not bear to ruin the career of a brave soldier, and I let things lie."
"And you--you received nothing?" asked Mollie, her cheeks on fire, her eyes glowing.
"I wanted a little money badly, and Keith gave me some out of his legacy. I could not resist the temptation of asking him for it. I don't want for a moment to pretend that I acted the hero. I did not; but compared with a man who could take the life of another, I was--"
"Very white indeed," said Mollie, with a curious, half-strangled laugh.
"Yes," he answered, "very white. We need not discuss that point. All this time I have lain low, and Keith has got on and forgotten the ghastly thing--he has engaged himself to a pretty young girl, and I have never said a word, and I never will say a word; on the contrary, I will do something else. On your wedding day I will make you, Mollie Hepworth, a present. I will give you those bottles out of which the medicines were taken. You shall destroy them, and so save Gavon Keith for ever. Will you marry me under these conditions?"