“This knocks out our only prop,” Markham said despondently, as we sped up Madison Avenue. “The possibility that the old lady was guilty was frightful to contemplate; though all along I’ve been trying to console myself with the thought that she was insane. Now, however, I almost wish our suspicions had proved true, for the possibilities that are left seem even more terrible. We’re dealing now with a cold-blooded calculating rationality.”
Vance nodded.
“Yes, we’re confronted with something far worse than mania. I can’t say, though, that I’m deeply shocked by Mrs. Greene’s death. She was a detestable woman, Markham—a most detestable woman. The world will not bemoan her loss.”
Vance’s comment expressed exactly the sentiment I had felt when Markham informed us of Mrs. Greene’s death. The news had of course shaken me, but I had no pity for the victim. She had been vicious and unnatural; she had thriven on hatred, and had made life a hell for everyone about her. It was better that her existence was over.
Both Heath and Drumm were waiting for us in the drawing-room. Excitement and depression were mingled in the Sergeant’s countenance, and the desperation of despair shone in his china-blue eyes. Drumm revealed only a look of professional disappointment: his chief concern apparently was that he had been deprived of an opportunity to display his medical skill.
Heath, after shaking hands absently, briefly explained the situation.
“O’Brien found the old dame dead at nine this morning, and told Sproot to wigwag to Doc Drumm. Then she phoned the Bureau, and I notified you and Doc Doremus. I got here fifteen or twenty minutes ago, and locked up the room.”
“Did you inform Von Blon?” Markham asked.
“I phoned him to call off the examination he’d arranged for ten o’clock. Said I’d communicate with him later, and hung up before he had time to ask any questions.”
Markham indicated his approval and turned toward Drumm.
“Give us your story, doctor.”
Drumm drew himself up, cleared his throat, and assumed an attitude calculated to be impressive.
“I was downstairs in the Narcoss dining-room eating breakfast when Hennessey came in and told me the curtains had gone down in the reception-room here. So I snatched my outfit and came over on the run. The butler took me to the old lady’s room, where the nurse was waiting. But right away I saw I was too late to be of any good. She was dead—contorted, blue, and cold—and rigor mortis had set in. Died of a big dose of strychnine. Probably didn’t suffer much—exhaustion and coma came inside of half an hour, I’d say. Too old, you understand, to throw it off. Old people succumb to strychnine pretty swiftly. …”
“What about her ability to cry out and give the alarm?”
“You can’t tell. The spasm may have rendered her mute. Anyway, no one heard her. Probably passed into unconsciousness after the first seizure. My experience with such cases has taught me—”
“What time would you say the strychnine was taken?”
“Well, now, you can’t tell exactly.” Drumm became oracular. “The convulsions may have been prolonged before death supervened, or death may have supervened very shortly after the poison was swallowed.”
“At what hour, then, would you fix the time of death?”
“There again you can’t say definitely. Confusion between rigor mortis and the phenomenon of cadaveric spasm is a pitfall into which many doctors fall. There are, however, distinct points of dissimilarity—”
“No doubt.” Markham was growing impatient with Drumm’s sophomoric pedantries. “But leaving all explanation to one side, what time do you think Mrs. Greene died?”
Drumm pondered the point.
“Roughly, let us say, at two this morning.”
“And the strychnine might have been taken as early as eleven or twelve?”
“It’s possible.”
“Anyhow, we’ll know about it when Doc Doremus gets here,” asserted Heath with brutal frankness. He was in vicious mood that morning.
“Did you find any glass or cup by which the drug might have been administered, doctor?” Markham hastened to ask, by way of covering up Heath’s remark.
“There was a glass near the bed with what appeared to be sulphate crystals adhering to the sides of it.”
“But wouldn’t a fatal dose of strychnine make an ordin’ry drink noticeably bitter?” Vance had suddenly become alert.
“Undoubtedly. But there was a bottle of citrocarbonate—a well-known antacid—on the night-table; and if the drug had been taken with this, the taste would not have been detected. Citrocarbonate is slightly saline and highly effervescing.”
“Could Mrs. Greene have taken the citrocarbonate alone?”
“It’s not likely. It has to be carefully mixed with water, and the operation would be highly awkward for anyone in bed.”
“Now, that’s most interestin’.” Vance listlessly lighted a cigarette. “We may presume, therefore, that the person who gave Mrs. Greene the citrocarbonate also administered the strychnine.” He turned to Markham. “I think Miss O’Brien might be able to help us.”
Heath went at once and summoned the nurse.
But her evidence was unilluminating. She had left Mrs. Greene reading about eleven o’clock, had gone to her own room to make her toilet for the night, and had returned to Ada’s room half an hour later, where she had slept all night, according to Heath’s instructions. She had risen at eight, dressed, and gone to the kitchen to fetch Mrs. Greene’s tea. As far as she knew, Mrs. Greene had drunk nothing before retiring—certainly she had taken no citrocarbonate up to eleven o’clock. Furthermore, Mrs. Greene never attempted to take it alone.
“You think, then,” asked Vance, “that it was given to her by someone else?”
“You can bank on it,” the nurse assured him bluntly. “If she’d wanted it, she’d have raised the house before mixing it herself.”
“It’s quite obvious,” Vance observed to Markham, “that someone entered her room after eleven o’clock and prepared the citrocarbonate.”
Markham got up
