It was a mystery to me, but not to the other doctors.  They took, as was natural, the worst possible view of the matter, and accepted the only solution which the facts seem to warrant.  But they are men, and I am a woman; besides, I knew the nurse well, and I could not believe her capable of wilful deceit, much less of the heinous crime which deceit in this case involved.  So to me the affair was a mystery.

The facts were these: 

My patient, a young typewriter, seemingly without friends or enemies, lay in a small room of a boarding-house, afflicted with a painful but not dangerous malady.  Though she was comparatively helpless, her vital organs were strong, and we never had a moment’s uneasiness concerning her, till one morning when we found her in an almost dying condition from having taken, as we quickly discovered, a dose of poison, instead of the soothing mixture which had been left for her with the nurse.  Poison! and no one, not even herself or the nurse, could explain how the same got into the room, much less into her medicine.  And when I came to study the situation, I found myself as much at loss as they; indeed, more so; for I knew I had made no mistake in preparing the mixture, and that, even if I had, this especial poison could not have found its way into it, owing to the fact that there neither was nor ever had been a drop of it in my possession.

The mixture, then, was pure when it left my hand, and, according to the nurse, whom, as I have said, I implicitly believe, it went into the glass pure.  And yet when, two hours later, without her having left the room or anybody coming into it, she found occasion to administer the draught, poison was in the cup, and the patient was only saved from death by the most immediate and energetic measures, not only on her part, but on that of Dr. Holmes, whom in her haste and perturbation she had called in from the adjacent house.

The patient, young, innocent, unfortunate, but of a strangely courageous disposition, betrayed nothing but the utmost surprise at the peril she had so narrowly escaped.  When Dr. Holmes intimated that perhaps she had been tired of suffering, and had herself found means of putting the deadly drug into her medicine, she opened her great gray eyes, with such a look of child-like surprise and reproach, that he blushed, and murmured some sort of apology.

“Poison myself?” she cried, “when you promise me that I shall get well?  You do not know what a horror I have of dying in debt, or you would never say that.”

This was some time after the critical moment had passed, and there were in the room Mrs. Dayton, the landlady, Dr. Holmes, the nurse, and myself.  At the utterance of these words we all felt ashamed and cast looks of increased interest at the poor girl.

She was very lovely.  Though without means, and to all appearance without friends, she possessed in great degree the charm of winsomeness, and not even her many sufferings, nor the indignation under which she was then laboring, could quite rob her countenance of that tender and confiding expression which so often redeems the plainest face and makes beauty doubly attractive.

“Dr. Holmes does not know you,” I hastened to say; “I do, and utterly repel for you any such insinuation.  In return, will you tell me if there is any one in the world whom you can call your enemy?  Though the chief mystery is how so deadly and unusual a poison could have gotten into a clean glass, without the knowledge of yourself or the nurse, still it might not be amiss to know if there is any one, here or elsewhere, who for any reason might desire your death.”

The surprise in the child-like eyes increased rather than diminished.

“I don’t know what to say,” she murmured.  “I am so insignificant and feeble a person that it seems absurd for me to talk of having an enemy.  Besides, I have none.  On the contrary, every one seems to love me more than I deserve.  Haven’t you noticed it, Mrs. Dayton?”

The landlady smiled and stroked the sick girl’s hand.

“Indeed,” she replied, “I have noticed that people love you, but I have never thought that it was more than you deserved.  You are a dear little thing, Addie.”

And though she knew and I knew that the “every one” mentioned by the poor girl meant ourselves, and possibly her unknown employer, we were none the less touched by her words.  The more we studied the mystery, the deeper and less explainable did it become.

And indeed I doubt if we should have ever got to the bottom of it, if there had not presently occurred in my patient a repetition of the same dangerous symptoms, followed by the same discovery, of poison in the glass, and the same failure on the part of herself and nurse to account for it.  I was aroused from my bed at midnight to attend her, and as I entered her room and met her beseeching eyes looking upon me from the very shadow of death, I made a vow that I would never cease my efforts till I had penetrated the secret of what certainly looked like a persistent attempt upon this poor girl’s life.

I went about the matter deliberately.  As soon as I could leave her side, I drew the nurse into a corner and again questioned her.  The answers were the same as before.  Addie had shown distress as soon as she had swallowed her usual quantity of medicine, and in a few minutes more was in a perilous condition.

“Did you hand the glass yourself to Addie?”

“I did.”

“Where did you take it from?”

“From the place where you left it ­the little stand on the farther side of the bed.”

“And do you mean to say that you had not touched it since I prepared it?”

“I do, ma’am.”

“And that no one else has been in the room?”

“No one, ma’am.”

I looked at her intently.  I trusted her, but the best of us are but mortal.

“Can you assure me that you have not been asleep during this time?”

“Look at this letter I have been writing,” she returned.  “It is eight pages long, and it was not begun when you left us at 10 o’clock.”

I shook my head and fell into a deep revery.  How was that matter to be elucidated, and how was my patient to be saved?  Another draught of this deadly poison, and no power on earth could resuscitate her.  What should I do, and with what weapons should I combat a danger at once so subtle and so deadly?  Reflection brought no decision, and I left the room at last, determined upon but one point, and that was the immediate removal of my patient.  But before I had left the house I changed my mind even on this point.  Removal of the patient meant safety to her, perhaps, but not the explanation of her mysterious poisoning.  I would change the position of her bed, and I would even set a watch over her and the nurse, but I would not take her out of the house ­not yet.

And what had produced this change in my plans?  The look of a woman whom I met on the stairs.  I did not know her, but when I encountered her glance I felt that there was some connection between us, and I was not at all surprised to hear her ask: 

“And how is Miss Wilcox to-day?”

“Miss Wilcox is very low,” I returned.  “The least neglect, the least shock to her nerves, would be sufficient to make all my efforts useless.  Otherwise ­”

“She will get well?”

I nodded.  I had exaggerated the condition of the sufferer, but some secret instinct compelled me to do so.  The look which passed over the woman’s face satisfied me that I had done well; and, though I left the house, it was with the intention of speedily returning and making inquiries into the woman’s character and position in the household.

I learned little or nothing.  That she occupied a good room and paid for it regularly seemed to be sufficient to satisfy Mrs. Dayton.  Her name, which proved to be Leroux, showed her to be French, and her promptly paid $10 a week showed her to be respectable ­what more could any hard-working landlady require?  But I was distrustful.  Her face, though handsome, possessed an eager, ferocious look which I could not forget, and the slight gesture with which she had passed me at the close of the short conversation I have given above had a suggestion of triumph in it which seemed to contain whole volumes of secret and mysterious hate.  I went into Miss Wilcox’s room very thoughtful.

“I am going ­”

But here the nurse held up her hand.  “Hark,” she whispered; she had just set the clock, and was listening to its striking.

I did hark, but not to the clock.

“Whose step is that?” I asked, after she had left the clock, and sat down.

“Oh, some one in the next room.  The walls here are very thin ­only boards in places.”

I did not complete what I had begun to say.  If I could hear steps through the partition, then could our neighbors hear us talk, and what I had determined upon must be kept secret from all outsiders.  I drew a sheet of paper toward me and wrote: 

“I shall stay here to-night.  Something tells me that in doing this I shall solve this mystery.  But I must appear to go.  Take my instructions as usual, and bid me good-night.  Lock the door after me, but with a turn of the key instantly unlock it again.  I shall go down stairs, see that my carriage drives away, and quietly return.  On my re-entrance I shall expect to find Miss Wilcox on the couch with the screen drawn up around it, you in your big chair, and the light lowered.  What I do thereafter need not concern you.  Pretend to go to sleep.”

The nurse nodded, and immediately entered upon the programme I had planned.  I prepared the medicine as usual, placed it in its usual glass, and laid that glass where it had always been set, on a small table at the farther side of the bed.  Then I said “Good-night,” and passed hurriedly out.

I was fortunate enough to meet no one, going or coming.  I regained the room, pushed open the door, and finding everything in order, proceeded at once to the bed, upon which, after taking off my hat and cloak and carefully concealing them, I lay down and deftly covered myself up.

My idea was this ­that by some mesmeric influence of which she was ignorant, the nurse had been forced to either poison the glass herself or open the door for another to do it.  If this were so, she or the other person would be obliged to pass around the foot of the bed in order to reach the glass, and I should be sure to see it, for I did not pretend to sleep.  By the low light enough could be discerned for safe movement about the room, and not enough to make apparent the change which had been made in the occupant of the bed.  I waited with indescribable anxiety, and more than once fancied I heard steps, if not a feverish breathing close to my bed-head; but no one appeared, and the nurse in her big chair did not move.

At last I grew weary, and fearful of losing control over my eyelids, I fixed my gaze upon the glass, as if in so doing I should find a talisman to keep me awake, when, great God! what was it I saw!  A hand, a creeping hand coming from nowhere and joined to nothing, closing about that glass and drawing it slowly away till it disappeared entirely from before my eyes!

I gasped ­I could not help it ­but I did not stir.  For now I knew I was asleep and dreaming.  But no, I pinch myself under the clothes, and find that I am very wide awake indeed; and then ­look! look! the glass is returning; the hand ­a woman’s hand ­is slowly setting it back in its place, and ­

With a bound I have that hand in my grasp.  It is a living hand, and it is very warm and strong and fierce, and the glass has fallen and lies shattered between us, and a double cry is heard, one from behind the partition, through an opening in which this hand had been thrust, and one from the nurse, who has jumped to her feet and is even now assisting me in holding the struggling member, upon which I have managed to scratch a tell-tale mark with a piece of the fallen glass.  At sight of the iron-like grip which this latter lays upon the intruding member, I at once release my own grasp.

“Hold on,” I cried, and leaping from the bed, I hastened first to my patient, whom I carefully reassured, and then into the hall, where I found the landlady running to see what was the matter.  “I have found the wretch,” I cried, and drawing her after me, hurried about to the other side of the partition, where I found a closet, and in it the woman I had met on the stairs, but glaring now like a tiger in her rage, menace, and fear.

That woman was my humble little patient’s bitter but unknown enemy.  Enamoured of a man who ­unwisely, perhaps ­had expressed in her hearing his admiration for the pretty typewriter, she had conceived the idea that he intended to marry the latter, and, vowing vengeance, had taken up her abode in the same house with the innocent girl, where, had it not been for the fortunate circumstance of my meeting her on the stairs, she would certainly have carried out her scheme of vile and secret murder.  The poison she had bought in another city, and the hole in the partition she had herself cut.  This had been done at first for the purpose of observation, she having detected in passing by Miss Wilcox’s open door that a banner of painted silk hung over that portion of the wall in such a way as to hide any aperture which might be made there.

Afterward, when Miss Wilcox fell sick, and she discovered by short glimpses through her loop-hole that the glass of medicine was placed on a table just under this banner, she could not resist the temptation to enlarge the hole to a size sufficient to admit the pushing aside of the banner and the reaching through of her murderous hand.  Why she did not put poison enough in the glass to kill Miss Wilcox at once I have never discovered.  Probably she feared detection.  That by doing as she did she brought about the very event she had endeavored to avert, is the most pleasing part of the tale.  When the gentleman of whom I have spoken learned of the wicked attempt which had been made upon Miss Wilcox’s life, his heart took pity upon her, and a marriage ensued, which I have every reason to believe is a happy one.