On the ninth of January, now four days ago, I received by the evening delivery a registered envelope, addressed in the hand of my colleague and old school companion, Henry Jekyll. I was a good deal surprised by this; for we were by no means in the habit of correspondence; I had seen the man, dined with him, indeed, the night before; and I could imagine nothing in our intercourse that should justify formality of registration. The contents increased my wonder; for this is how the letter ran:

“10th December, 18—.

“Dear Lanyon,—You are one of my oldest friends; and although we may have differed at times on scientific questions, I cannot remember, at least on my side, any break in our affection. There was never a day when, if you had said to me, `Jekyll, my life, my honour, my reason, depend upon you,’ I would not have sacrificed my left hand to help you. Lanyon my life, my honour, my reason, are all at your mercy; if you fail me to-night, I am lost. You might suppose, after this preface, that I am going to ask you for something dishonourable to grant. Judge for yourself.

“I want you to postpone all other engagements for to-night—ay, even if you were summoned to the bedside of an emperor; to take a cab, unless your carriage should be actually at the door; and with this letter in your hand for consultation, to drive straight to my house. Poole, my butler, has his orders; you will find him waiting your arrival with a locksmith. The door of my cabinet is then to be forced: and you are to go in alone; to open the glazed press (letter E) on the left hand, breaking the lock if it be shut; and to draw out, with all its contents as they stand, the fourth drawer from the top or (which is the same thing) the third from the bottom. In my extreme distress of mind, I have a morbid fear of misdirecting you; but even if I am in error, you may know the right drawer by its contents: some powders, a phial and a paper book. This drawer I beg of you to carry back with you to Cavendish Square exactly as it stands.

“That is the first part of the service: now for the second. You should be back, if you set out at once on the receipt of this, long before midnight; but I will leave you that amount of margin, not only in the fear of one of those obstacles that can neither be prevented nor foreseen, but because an hour when your servants are in bed is to be preferred for what will then remain to do. At midnight, then, I have to ask you to be alone in your consulting room, to admit with your own hand into the house a man who will present himself in my name, and to place in his hands the drawer that you will have brought with you from my cabinet. Then you will have played your part and earned my gratitude completely. Five minutes afterwards, if you insist upon an explanation, you will have understood that these arrangements are of capital importance; and that by the neglect of one of them, fantastic as they must appear, you might have charged your conscience with my death or the shipwreck of my reason.

“Confident as I am that you will not trifle with this appeal, my heart sinks and my hand trembles at the bare thought of such a possibility. Think of me at this hour, in a strange place, labouring under a blackness of distress that no fancy can exaggerate, and yet well aware that, if you will but punctually serve me, my troubles will roll away like a story that is told. Serve me, my dear Lanyon and save

“Your friend,

“H.J.

“P.S.—I had already sealed this up when a fresh terror struck upon my soul. It is possible that the post-office may fail me, and this letter not come into your hands until to-morrow morning. In that case, dear Lanyon, do my errand when it shall be most convenient for you in the course of the day; and once more expect my messenger at midnight. It may then already be too late; and if that night passes without event, you will know that you have seen the last of Henry Jekyll.”

Upon the reading of this letter, I made sure my colleague was insane; but till that was proved beyond the possibility of doubt, I felt bound to do as he requested. The less I understood of this farrago, the less I was in a position to judge of its importance; and an appeal so worded could not be set aside without a grave responsibility. I rose accordingly from table, got into a hansom, and drove straight to Jekyll’s house. The butler was awaiting my arrival; he had received by the same post as mine a registered letter of instruction, and had sent at once for a locksmith and a carpenter. The tradesmen came while we were yet speaking; and we moved in a body to old Dr. Denman’s surgical theatre, from which (as you are doubtless aware) Jekyll’s private cabinet is most conveniently entered. The door was very strong, the lock excellent; the carpenter avowed he would have great trouble and have to do much damage, if force were to be used; and the locksmith was near despair. But this last was a handy fellow, and after two hour’s work, the door stood open. The press marked E was unlocked; and I took out the drawer, had it filled up with straw and tied in a sheet, and returned with it to Cavendish Square.

Here I proceeded to examine its contents. The powders were neatly enough made up, but not with the nicety of the dispensing chemist; so that it was plain they were of Jekyll’s private manufacture: and when I opened one of the wrappers I found what seemed to me a simple crystalline salt of a white colour. The phial, to which I next turned my attention, might have been about half full of a blood-red liquor, which was highly pungent to the sense of smell and seemed to me to contain phosphorus and some volatile ether. At the other ingredients I could make no guess. The book was an ordinary version book and contained little but a series of dates. These covered a period of many years, but I observed that the entries ceased nearly a year ago and quite abruptly. Here and there a brief remark was appended to a date, usually no more than a single word: “double” occurring perhaps six times in a total of several hundred entries; and once very early in the list and followed by several marks of exclamation, “total failure!!!” All this, though it whetted my curiosity, told me little that was definite. Here were a phial of some salt, and the record of a series of experiments that had led (like too many of Jekyll’s investigations) to no end of practical usefulness. How could the presence of these articles in my house affect either the honour, the sanity, or the life of my flighty colleague? If his messenger could go to one place, why could he not go to another? And even granting some impediment, why was this gentleman to be received by me in secret? The more I reflected the more convinced I grew that I was dealing with a case of cerebral disease; and though I dismissed my servants to bed, I loaded an old revolver, that I might be found in some posture of self-defence.

Twelve o’clock had scarce rung out over London, ere the knocker sounded very gently on the door. I went myself at the summons, and found a small man crouching against the pillars of the portico.

“Are you come from Dr. Jekyll?” I asked.

He told me “yes” by a constrained gesture; and when I had bidden him enter, he did not obey me without a searching backward glance into the darkness of the square. There was a policeman not far off, advancing with his bull’s eye open; and at the sight, I thought my visitor started and made greater haste.

These particulars struck me, I confess, disagreeably; and as I followed him into the bright light of the consulting room, I k............