"I don't understand you," he said.
"You will soon, if you listen. Of course it was an accident, and a deplorable one, but you, Keith, gave that poor lad the wrong medicine."
"Oh, horror!" cried Keith. He sprang to his feet. A terrible weakness seized him; his head seemed to go round; he clutched a chair to keep himself from falling. "What do you mean?" he added.
"What I say," answered Strause, who read these signs of agitation with pleasure. "It happens that I am in a position to prove my words. You know I was nursing Aylmer all day until you arrived and interfered. Your interference was unwarrantable; but I say nothing of that. I had been giving Aylmer his medicines, and happened to know exactly the amount in each bottle. The alterative medicine, as it is called, had just been renewed, but the bottle containing the opiate was more than half full. The opiate was in the smaller bottle, as you know. The alterative medicine was to be given in tablespoonfuls—two tablespoonfuls to a dose. At the time I gave up my charge of Aylmer to you there were in the larger bottle five doses, but the bottle which contained the opiate was a little less than half full. Do you follow me?"
"I hear you, but I cannot imagine what you are driving at."
"You will soon know. On the morning of the death you were terribly agitated. I rushed off to the poor lad's quarters when I heard the news, and found that you had left, saying that you would be round again presently. I went to the table where the medicines stood, and casually took up the bottle which contained the opiate. The moment I saw it I opened my eyes. The bottle was very nearly empty! Even allowing for your giving him a teaspoonful at a time, it was absolutely impossible that he could have taken anything like the amount which was now gone. I then looked at the other bottle, and found that only one teaspoonful had been taken from it since you had charge of the case. You follow me, don't you? In the bottle which contained the alterative medicine there were still four doses; in the bottle which contained the opiate there was not more than a teaspoonful left. Beyond doubt what happened was this: you gave Aylmer, quite by mistake, two tablespoonfuls of the opiate—a dose which of course caused his death."
"You lie!" said Keith. "How dare you come to this room with that trumped-up story? I did not make a mistake with regard to the medicines. I was most careful, and I am prepared to swear in any court that I took two tablespoonfuls of the alterative medicine, which was in the larger bottle, and brought it to Aylmer between nine and ten o'clock that night."
"Swear it, then," said Strause, in a contemptuous voice, with a sneer on his lips, and a malicious light in his eyes which caused Keith to recoil from him as though he were a serpent—"swear it, and go right through with the whole thing. I have the bottles in my possession, and although there are no witnesses on either side, believe me it will be at best a nasty case for you. You were alone with the sick man—you gave him a fatal dose of the wrong medicine—you were remembered in the poor fellow's will to the somewhat unusual tune of ten thousand pounds. My fine fellow, you are in my power. Even supposing the murder is never brought home to you, your career as an officer in the North Essex Light Infantry is over."
As Strause said the last words he left the room, swaggering out with his usual gait.
Keith sank into a chair and pressed both his hands to his throbbing temples. Was this true?