THE following day was one that will ever remain in my memory. Despite the fact that what happened had been foreseen by all of us, nevertheless when it actually came it left us as completely stunned as if it had been wholly unexpected. Indeed, the very horror that informed our anticipation tended to intensify the enormity of the event.

    The day broke dark and threatening. A damp chill was in the air; and the leaden skies clung close to the earth with suffocating menace. The weather was like a symbol of our gloomy spirits.

    Vance rose early, and, though he said little, I knew the case was preying on his mind. After breakfast he sat before the fire for over an hour sipping his coffee and smoking. Then he made an attempt to interest himself in an old French edition of "Till Ulenspiegel," but, failing, took down volume seven of Osler's "Modern Medicine" and turned to Buzzard's article on myelitis. For an hour he read with despairing concentration. At last he returned the book to the shelves.

    At half-past eleven Markham telephoned to inform us that he was leaving the office immediately for the Greene mansion and would stop en route to pick us up. He refused to say more, and hung up the receiver abruptly.

    It wanted ten minutes of being noon when he arrived; and his expression of grim discouragement told us more plainly than words that another tragedy had occurred.

    We had on our coats in readiness and accompanied him at once to the car.

    "And who is it this time?" asked Vance, as we swung into Park Avenue.

    "Ada." Markham spoke bitterly through his teeth.

    "I was afraid of that, after what she told us yesterday.—With poison, I suppose."

    "Yes—the morphine."

    "Still, it's an easier death than strychnine-poisoning."

    "She's not dead, thank God!" said Markham. "That is, she was still alive when Heath phoned."

    "Heath? Was he at the house?"

    "No. The nurse notified him at the Homicide Bureau, and he phoned me from there. He'll probably be at the Greenes' when we arrive."

    "You say she isn't dead?"

    "Drumm—he's the official police surgeon Moran stationed in the Narcoss Flats—got there immediately, and had managed to keep her alive up to the time the nurse phoned."

    "Sproot's signal worked all right, then?"

    "Apparently. And I want to say, Vance, that I'm damned grateful to you for that suggestion to have a doctor on hand."

    When we arrived at the Greene mansion Heath, who had been watching for us, opened the door.

    "She ain't dead," he greeted us in a stage whisper; and then drew us into the reception-room to explain his secretive manner. "Nobody in the house except Sproot and O'Brien knows about this poisoning yet. Sproot found her, and then pulled down all the front curtains in this room—which was the signal agreed on. When Doc Drumm hopped across Sproot was waiting with the door open, and took him upstairs without anybody seeing him. The doc sent for O'Brien, and after they'd worked on the girl for a while he told her to notify the Bureau. They're both up in the room now with the doors locked."

    "You did right in keeping the thing quiet," Markham told him. "If Ada recovers we can hush it up and perhaps learn something from her."

    "That's what I was thinking, sir. I told Sproot I'd wring his scrawny neck if he spilled anything to anybody."

    "And," added Vance, "he bowed politely and said 'Yes, sir.'"

    "You bet your life he did!"

    "Where is the rest of the household at present?" Markham asked.

    "Miss Sibella's in her room. She had breakfast in bed at half-past ten and told the maid she was going back to sleep. The old lady's also asleep. The maid and the cook are in the back of the house somewhere."

    "Has Von Blon been here this morning?" put in Vance.

    "Sure he's been here—he comes regular. O'Brien said he called at ten, sat with the old lady about an hour, and then went away."

    "And he hasn't been notified about the morphine?"

    "What's the use? Drumm's a good doctor, and Von Blon might blab about it to Sibella or somebody."

    "Quite right." Vance nodded his approval.

    We re-entered the hall and divested ourselves of our wraps.

    "While we're waiting for Doctor Drumm," said Markham, "we might as well find out what Sproot knows."

    We went into the drawing-room, and Heath yanked the bell-cord. The old butler came directly and stood before us without the slightest trace of emotion. His imperturbability struck me as inhuman.

    Markham beckoned him to come nearer.

    "Now, Sproot, tell us exactly what took place."

    "I was in the kitchen resting, sir"—the man's voice was as wooden as usual—"and I was just looking at the clock and thinking I would resume my duties, when the bell of Miss Ada's room rang. Each bell, you understand, sir—"

    "Never mind that! What time was it?"

    "It was exactly eleven o'clock. And, as I said, Miss Ada's bell rang. I went right upstairs and knocked on her door; but, as there was no answer, I took the liberty of opening it and looking into the room. Miss Ada was lying on the bed; but it was not a natural attitude—if you understand what I mean. And then I noticed a very peculiar thing, sir. Miss Sibella's little dog was on the bed—"

    "Was there a chair or stool by the bed?" interrupted Vance.

    "Yes, sir, I believe there was. An ottoman."

    "So the dog could have climbed on the bed unassisted?"

    "Oh, yes, sir."

    "Very good. Continue."

    "Well, the dog was on the bed, and he looked like he was standing on his hind legs playing with the bell-cord. But the peculiar thing was that his hind legs were on Miss Ada's face, and she didn't seem to even notice it. Inwardly I was a bit startled; and I went to the bed and picked up the dog. Then I discovered that several threads of the silk tassel on the end of the cord had got caught between his teeth; and-would you believe it, sir?-it was him who had really rung Miss Ada's bell..."

    "Amazin'," murmured Vance. "What then, Sproot?"

    "I shook the young lady, although I had little hope of waking her after Miss Sibella's dog had been trampling over her face without her knowing it. Then I came downstairs and drew the curtains in the reception-room as I had been instructed to do in case of an emergency. When the doctor arrived I showed him to Miss Ada's room."

    "And that's all you know?"

    "Everything, sir."

    "Thank you, Sproot." Markham rose impatiently.

    "And now you might let Doctor Drumm know that we are here."

    It was the nurse, however, who came to the drawing-room a few minutes later. She was a medium-sized, well-built woman of thirty-five, with shrewd brown eyes, a thin mouth, and a firm chin, and a general air of competency. She greeted Heath with a companionable wave of the hand and bowed to the rest of us with aloof formality.

    "Doc Drumm can't leave his patient just now," she informed us, seating herself. "So he sent me along. He'll be down presently."

    "And what's the report?" Markham was still standing.

    "She'll live, I guess. We've been giving her passive exercise and artificial breathing for half an hour, and the doc hopes to have her walking before long."

    Markham, his nervousness somewhat abated, sat down again.

    "Tell us all you can, Miss O'Brien. Was there any evidence as to how the poison was administered?"

    "Nothing but an empty bouillon cup." The woman was ill at ease. "I guess you'll find remains of morphine in it, all right."

    "Why do you think the drug was given by means of the bouillon?"

    She hesitated and shot Heath an uneasy look.

    "It's this way. I always bring a cup of bouillon to Mrs. Greene a little before eleven in the morning; and if Miss Ada's around I bring two cups— that's the old lady's orders. This morning the girl was in the room when I went down to the kitchen, so I brought up two cups. But Mrs. Greene was alone when I returned, so I gave the old lady hers and put the other cup in Miss Ada's room on the table by the bed. Then I went into the hall to call her. She was downstairs—in the living-room, I guess. Anyhow, she came up right away, and, as I had some mending to do for Mrs. Greene, I went to my room on the third floor..."

    "Therefore," interpolated Markham, "the bouillon was on Miss Ada's table unprotected for a minute or so after you had left the room and before Miss Ada came up from the lower hall."

    "It wasn't over twenty seconds. And I was right outside the door all the time. Furthermore, the door was open, and I'd have heard anyone in the room." The woman was obviously defending herself desperately against the imputation of negligence in Markham's remark.

    Vance put the next question.

    "Did you see anyone else in the hall besides Miss Ada?"

    "No one except Doctor Von Blon. He was in the lower hall getting into his coat when I called down."

    "Did he leave the house at once?"

    "Why—yes."

    "You actually saw him pass through the door?"

    "No—o. But he was putting on his coat, and he had said good bye to Mrs. Greene and me..."

    "When?"

    "Not two minutes before. I'd met him coming out of Mrs. Greene's door just as I brought in the bouillon."

    "And Miss Sibella's dog—did you notice it in the hall anywhere?"

    "No; it wasn't around when I was there."

    Vance lay back drowsily in his chair, and Markham again took up the interrogation.

    "How long did you remain in your room, Miss O'Brien, after you had called Miss Ada?"

    "Until the butler came and told me that Doctor Drumm wanted me."

    "And how much later would you say that was?"

    "About twenty minutes—maybe a little longer."

    Markham smoked pensively a while.

    "Yes," he commented at length; "it plainly appears that the morphine was somehow added to the bouillon.—You'd better return to Doctor Drumm now, Miss O'Brien. We'll wait here for him."

    "Hell!" growled Heath, after the nurse had gone upstairs. "She's the best woman for this sort of a job that we've got. And now she goes and falls down on it."

    "I wouldn't say she'd fallen down exactly, Sergeant." dissented Vance, his eyes fixed dreamily on the ceiling. "After all, she only stepped into the hall for a few seconds to summon the young lady to her matutinal broth. And if the morphine hadn't found its way into the bouillon this morning it would have done so to-morrow, or the day after, or some time in the future. In fact, the propitious gods may actually have favoured us this morning as they did the Grecian host before the walls of Troy."

    "They will have favoured us," observed Markham, "if Ada recovers and can tell us who visited her room before she drank the bouillon."

    The silence that ensued was terminated by the entrance of Doctor Drumm, a youthful, earnest man with an aggressive bearing. He sank heavily into a chair and wiped his face with a large silk handkerchief.

    "She's pulled through," he announced. "I happened to be standing by the window looking out—sheer chance—when I saw the curtains go down—saw 'em before Hennessey[22] did. I grabbed up my bag and the pulmotor, and was over here in a jiffy. The butler was waiting at the door, and took me upstairs. Queer crab, that butler. The girl was lying across the bed, and it didn't take but one look to see that I wasn't dealing with strychnine. No spasms or sweating or risus sardonicus, you understand. Quiet and peaceful; shallow breathing; cyanosis. Morphine evidently. Then I looked at her pupils. Pinpoints. No doubt now. So I sent for the nurse and got busy."

    "A close call?" asked Markham.

    "Close enough." The doctor nodded importantly. "You can't tell what would have happened if somebody hadn't got to her in a hurry. I figured she'd got all six grains that were lost, and gave her a good stiff hypo of atropine—a fiftieth. It reacted like a shot. Then I washed her stomach out with potassium permanganate. After that I gave her artificial respiration—she didn't seem to need it, but I wasn't taking any chances. Then the nurse and I got busy exercising her arms and legs, trying to keep her awake. Tough work, that. Hope I don't get pneumonia sweating there with the windows all open... Well, so it went. Her breathing kept getting better, and I gave her another hundredth of atropine for good measure. At last I managed to get her on her feet. The nurse is walking her up and down now." He mopped his face again with a triumphant flourish of the handkerchief.

    "We're greatly indebted to you, doctor," said Markham. "It's quite possible you have been the means of solving this case.—When will we be able to question your patient?"

    "She'll be loggy and nauseated all day—kind of general collapse, you understand, with painful breathing, drowsiness, headache, and that sort of thing—no fit condition to answer questions. But to-morrow morning you'll be able to talk to her as much as you like."

    "That will be satisfactory. And what of the bouillon cup the nurse mentioned?"

    "It tasted bitter—morphine, all right."

    As Drumm finished speaking Sproot passed down the hall to the front door. A moment later Von Blon paused at the archway and looked into the drawing-room. The strained silence which followed the exchange of greetings caused him to study us with growing alarm.

    "Has anything happened?" he finally asked.

    It was Vance who rose and, with quick decision, assumed the rôle of spokesman.

    "Yes, doctor. Ada has been poisoned with morphine. Doctor Drumm here happened to be in the Narcoss Flats opposite and was called in."

    "And Sibella—is she all right?" Von Blon spoke excitedly.

    "Oh, quite."

    A relieved sigh escaped him, and he sank into a chair. "Tell me about it. When was the—the murder discovered?"

    Drumm was about to correct him when Vance said quickly:

    "Immediately after you left the house this morning. The poison was administered in the bouillon the nurse brought from the kitchen."

    "But... how could that be?" Von Blon appeared unbelieving. "I was just going when she brought the bouillon. I saw her enter with it. How could the poison—?"

    "That reminds me, doctor." Vance's tone was almost dulcet. "Did you, by any hap, go upstairs again after you had donned your coat?"

    Von Blon looked at him with outraged astonishment. "Certainly not! I left the house immediately."

    "That would have been just after the nurse called down to Ada."

    "Why—yes. I believe the nurse did call down; and Ada went upstairs at once—if I recall correctly."

    Vance smoked a moment, his gaze resting curiously on the doctor's troubled face.

    "I would suggest, without any intention of being impertinent, that your present visit follows rather closely upon your former one."

    Von Blon's face clouded over, but I failed to detect any resentment in his expression.

    "Quite true," he rejoined, and shifted his eyes. "The fact is, sir, that ever since those drugs disappeared from my case I've felt that something tragic was impending, and that I was in some way to blame. Whenever I'm in this neighbourhood I can't resist the impulse to call here and—and see how things are going."

    "Your anxiety is wholly understandable." Vance's tone was non-committal. Then he added negligently: "I suppose you will have no objection to Doctor Drumm continuing with Ada's case."

    "Continuing?" Von Blon brought himself up straight in his chair. "I don't understand. You said a moment ago—"

    "That Ada had been poisoned," finished Vance. "Quite. But d'ye see, she didn't die."

    The other looked dumbfounded.

    "Thank God for that!" he exclaimed, rising nervously.

    "And," added Markham, "we are making no mention whatever of the episode. You will, therefore, be guided by our decision."

    "Of course.—And is it permitted that I see Ada?"

    Markham hesitated, and Vance answered:

    "If you care to—certainly." He turned to Drumm. "Will you be so good as to accompany Doctor Von Blon?"

    Drumm and Von Blon left the room together.

    "I don't wonder he's on edge," commented Markham. "It's not pleasant to learn of people being poisoned with drugs lost through one's own carelessness."

    "He wasn't worrying as much over Ada as he was over Sibella," remarked Heath.

    "Observin' fella!" smiled Vance. "No, Sergeant; Ada's demise apparently bothered him far less than Sibella's possible state of health... Now, I wonder what that means. It's an inveiglin' point. But—dash it all—it everts my pet theory."

    "So you have a theory." Markham spoke rebukingly.

    "Oh, any number of 'em. And, I might add, they're all pets." Vance's lightness of tone meant merely that he was not ready to outline his suspicions; and Markham did not push the matter.

    "We won't need any theories," declared Heath, "after we've heard what Ada's got to tell us. As soon as she talks to us to-morrow we'll be able to figure out who poisoned her"

    "Perhaps," murmured Vance.

    Drumm returned alone a few minutes later.

    "Doctor Von Blon has stepped into the other girl's room. Said he'd be down right away."

    "What did he have to say about your patient?" asked Vance.

    "Nothing much. She put new energy into her walking the minute she saw him, though. Smiled at him, too, by Jove! A good sign, that. She'll come through fast. Lot of resistance in her."

    Drumm had hardly ceased speaking when we heard Sibella's door close and the sound of descending footsteps on the stairs.

    "By the by, doctor," said Vance to Von Blon as the latter re-entered the drawing-room, "have you seen Oppenheimer yet?"

    I saw him at eleven. The fact is, I went direct to him after leaving here this morning. He has agreed to make an examination to-morrow at ten o'clock."

    "And was Mrs. Greene agreeable?"

    "Oh, yes. I spoke to her about it this morning; and she made no objection whatever."

    A short while later we took our departure. Von Blon accompanied us to the gate, and we saw him drive off in his car.

    "We'll know more by this time to-morrow, I hope," said Markham on the way down-town. He was unwontedly depressed, and his eyes were greatly troubled. "You know, Vance, I'm almost appalled by the thought of what Oppenheimer's report may be."

    No report was ever made by Doctor Oppenheimer, however. At some time between one and two the next morning Mrs. Greene died in convulsions as a result of strychnine poisoning.