Many years ago, on my way from Hong Kong to New York, I passed a week in San Francisco. A long time had gone by since I had been in that city, during which my ventures in the Orient had prospered beyond my hope; I was rich and could afford to revisit my own country to renew my friendship with such of the companions of my youth as still lived and remembered me with the old affection. Chief of these, I hoped, was Mohun Dampier, an old schoolmate with whom I had held a desultory correspondence which had long ceased, as is the way of correspondence between men. You may have observed that the indisposition to write a merely social letter is in the ratio of the square of the distance between you and your correspondent. It is a law.

I remembered Dampier as a handsome, strong young fellow of scholarly tastes, with an aversion to work and a marked indifference to many of the things that the world cares for, including wealth, of which, however, he had inherited enough to put him beyond the reach of want. In his family, one of the oldest and most aristocratic in the country, it was, I think, a matter of pride that no member of it had ever been in trade nor politics, nor suffered any kind of distinction. Mohan was a trifle sentimental, and had in him a singular element of superstition, which led him to the study of all manner of occult subjects, although his sane mental health safeguarded him against fantastic and perilous faiths. He made daring incursions into the realm of the unreal without renouncing his residence in the partly surveyed and charted region of what we are pleased to call certitude.

The night of my visit to him was stormy. The Californian winter was on, and the incessant rain splashed in the deserted streets, or, lifted by irregular gusts of wind, was hurled against the houses with incredible fury. With no small difficulty my cabman found the right place, away out toward the ocean beach, in a sparsely populated suburb. The dwelling, a rather ugly one, apparently, stood in the centre of its grounds, which as nearly as I could make out in the gloom were destitute of either flowers or grass. Three or four trees, writhing and moaning in the torment of the tempest, appeared to be trying to escape from their dismal environment and take the chance of finding a better one out at sea. The house was a two-story brick structure with a tower, a story higher, at one corner. In a window of that was the only visible light. Something in the appearance of the place made me shudder, a performance that may have been assisted by a rill of rainwater down my back as I scuttled to cover in the doorway.

In answer to my note apprising him of my wish to call, Dampier had written, 'Don't ring - open the door and come up.' I did so. The staircase was dimly lighted by a single gas-jet at the top of the second flight. I managed to reach the landing without disaster and entered by an open door into the lighted square room of the tower. Dampier came forward in gown and slippers to receive me, giving me the greeting that I wished, and if I had held a thought that it might more fitly have been accorded me at the front door the first look at him dispelled any sense of his inhospitality.

He was not the same. Hardly past middle age, he had gone grey and had acquired a pronounced stoop. His figure was thin and angular, his face deeply lined, his complexion dead-white, without a touch of colour. His eyes, unnaturally large, glowed with a fire that was almost uncanny.

He seated me, proffered a cigar, and with grave and obvious sincerity assured me of the pleasure that it gave him to meet me. Some unimportant conversation followed, but all the while I was dominated by a melancholy sense of the great change in him. This he must have perceived, for he suddenly said with a bright enough smile, 'You are disappointed in me - /non sum qualis eram./'

I hardly knew what to reply, but managed to say: 'Why, really, I don't know: your Latin is about the same.'

He brightened again. 'No,' he said, 'being a dead language, it grows in appropriateness. But please have the patience to wait: where I am going there is perhaps a better tongue. Will you care to have a message in it?'

The smile faded as he spoke, and as he concluded he was looking into my eyes with a gravity that distressed me. Yet I would not surrender myself to his mood, nor permit him to see how deeply his prescience of death affected me.

'I fancy that it will be long,' I said, 'before human speech will cease to serve our need; and then the need, with its possibilities of service, will have passed.'

He made no reply, and I too was silent, for the talk had taken a dispiriting turn, yet I knew not how to give it a more agreeable character. Suddenly, in a pause of the storm, when the dead silence was almost startling by contrast with the previous uproar, I heard a gentle tapping, which appeared to come from the wall behind my chair. The sound was such as might have been made by a human hand, not as upon a door by one asking admittance, but rather, I thought, as an agreed signal, an assurance of someone's presence in an adjoining room; most of us, I fancy, have had more experience of such communications than we should care to relate. I glanced at Dampier. If possibly there was something of amusement in the look he did not observe it. He appeared to have forgotten my presence, and was staring at the wall behind me with an expression in his eyes that I am unable to name, although my memory of it is as vivid to-day as was my sense of it then. The situation was embarrassing! ; I rose to take my leave. At this he seemed to recover himself.

'Please be seated,' he said; 'it is nothing - no one is there.'

But the tapping was repeated, and with the same gentle, slow insistence as before.

'Pardon me,' I said, 'it is late. May I call tomorrow?'

He smiled - a little mechanically, I thought. 'It is very delicate of you,' said he, 'but quite needless. Really, this is the only room in the tower, and no one is there. At least -' He left the sentence incomplete, rose, and threw up a window, the only opening in the wall from which the sound seemed to come. 'See.'

Not clearly knowing what else to do I followed him to the window and looked out. A street-lamp some little distance away gave enough light through the murk of the rain that was again falling in torrents to make it entirely plain that 'no one was there.' In truth there was nothing but the sheer blank wall of the tower.

Dampier closed the window and signing me to my seat resumed his own.

The incident was not in itself particularly mysterious; any one of a dozen explanations was possible (though none has occurred to me), yet it impressed me strangely, the more, perhaps, from my friend's effort to reassure me, which seemed to dignify it with a certain significance and importance. He had proved that no one was there, but in that fact lay all the interest; and he proffered no explanation. His silence was irritating and made me resentful.

'My good friend,' I said, somewhat ironically, I fear, 'I am not disposed to question your right to harbour as many spooks as you find agreeable to your taste and consistent with your notions of companionship; that is no business of mine. But being just a plain man of affairs, mostly of this world, I find spooks needless to my peace and comfort. I am going to my hotel, where my fellow-guests are still in the flesh.'

It was not a very civil speech, but he manifested no feeling about it. 'Kindly remain', he said. 'I am grateful for your presence here. What you have heard to-night I believe myself to have heard twice before. Now I /know/ it was no illusion. That is much to me - more than you know. Have a fresh cigar and a good stock of patience while I tell you the story.'

The rain was now falling more steadily, with a low, monotonous susurration, interrupted at long intervals by the sudden slashing of the boughs of the trees as the wind rose and failed. The night was well advanced, but both sympathy and curiosity held me a willing listener to my friend's monologue, which I did not interrupt by a single word from beginning to end.

'Ten years ago,' he said, 'I occupied a ground-floor apartment in one of a row of houses, all alike, away at the other end of the town, on what we call Rincon Hill. This had been the best quarter of San Francisco, but had fallen into neglect and decay, partly because the primitive character of its domestic architecture no longer suited the maturing tastes of our wealthy citizens, partly because certain public improvements had made a wreck of it. The row of dwellings in one of which I lived stood a little way back from the street, each having a miniature garden, separated from its neighbours by low iron fences and bisected with mathematical precision by a box-bordered gravel walk from gate to door.

'One morning as I was leaving my lodging I observed a young girl entering the adjoining garden on the left. It was a warm day in June, and she was lightly gowned in white. From her shoulders hung a broad straw hat profusely decorated with flowers and wonderfully beribboned in the fashion of the time. My attention was not long held by the exquisite simplicity of her costume, for no one could look at her face and think of anything earthly. Do not fear; I shall not profane it by description; it was beautiful exceedingly. All that I had ever seen or dreamed of loveliness was in that matchless living picture by the hand of the Divine Artist. So deeply did it move me that, without a thought of the impropriety of the act, I unconsciously bared my head, as a devout Catholic or well-bred Protestant uncovers before an image of the Blessed Virgin. The maiden showed no displeasure; she merely turned her glorious dark eyes upon me with a look that made me catch my breath, and without other recognition of my act passed into the house. For a moment I stood motionless, hat in hand, painfully conscious of my rudeness, yet so dominated by the emotion inspired by that vision of incomparable beauty that my penitence was less poignant than it should have been. Then I went my way, leaving my heart behind. In the natural course of things I should probably have remained away until nightfall, but by the middle of the afternoon I was back in the little garden, affecting an interest in the few foolish flowers that I had never before observed. My hope was vain; she did not appear.

'To a night of unrest succeeded a day of expectation and disappointment, but on the day after, as I wandered aimlessly about the neighbourhood, I met her. Of course I did not repeat my folly of uncovering, nor venture by even so much as too long a look to manifest an interest in her; yet my heart was beating audibly. I trembled and consciously coloured as she turned her big black eyes upon me with a look of obvious recognition entirely devoid of boldness or coquetry.

'I will not weary you with particulars; many times afterward I met the maiden, yet never either addressed her or sought to fix her attention. Nor did I take any action toward making her acquaintance. Perhaps my forbearance, requiring so supreme an effort of self-denial, will not be entirely clear to you. That I was heels over head in love is true, but who can overcome his habit of thought, or reconstruct his character?

'I was what some foolish persons are pleased to call, and others, more foolish, are pleased to be called - an aristocrat; and despite her beauty, her charms and graces, the girl was not of my class. I had learned her name - which it is needless to speak - and something of her family. She was an orphan, a dependent niece of the impossible elderly fat woman in whose lodging-house she lived. My income was small and I lacked the talent for marrying; it is perhaps a gift. An alliance with that family would condemn me to its manner of life, part me from my books and studies, and in a social sense reduce me to the ranks. It is easy to deprecate such considerations as these and I have not retained myself for the defence. Let judgement be entered against me, but in strict justice all my ancestors for generations should be made co-defendants and I be permitted to plead in mitigation of punishment the imperious mandate of heredity. To a mésalliance of that kind every globule of my ancestral blood spoke in opposition. In brief, my tastes, habits, instinct, with whatever of reason my love had left me - all fought against it. Moreover, I was an irreclaimable sentimentalist, and found a subtle charm in an impersonal and spiritual relation which acquaintance might vulgarise and marriage would certainly dispel. No woman, I argued, is what this lovely creature seems. Love is a delicious dream; why should I bring about my own awakening?

'The course dictated by all this sense and sentiment was obvious. Honour, pride, prudence, preservation of my ideals - all commanded me to go away, but for that I was too weak. The utmost that I could do by a mighty effort of will was to cease meeting the girl, and that I did. I even avoided the chance encounters of the garden, leaving my lodging only when I knew that she had gone to her music lessons, and returning after nightfall. Yet all the while I was as one in a trance, indulging the most fascinating fancies and ordering my entire intellectual life in accordance with my dream. Ah, my friend, as one whose actions have a traceable relation to reason, you cannot know the fool's paradise in which I lived.

'One evening the devil put it into my head to be an unspeakable idiot. By apparently careless and purposeless questioning I learned from my gossipy landlady that the young woman's bedroom adjoined my own, a partywall between. Yielding to a sudden and coarse impulse I gently rapped on the wall. There was no response, naturally, but I was in no mood to accept a rebuke. A madness was upon me and I repeated the folly, the offence, but again ineffectually, and I had the decency to desist.

'An hour later, while absorbed in some of my infernal studies, I heard, or thought I heard, my signal answered. Flinging down my books I sprang to the wall and as steadily as my beating heart would permit gave three slow taps upon it. This time the response was distinct, unmistakable: one, two, three - an exact repetition of my signal. That was all I could elicit, but it was enough - too much.

'The next evening, and for many evenings afterward, that folly went on, I always having "the last word". During the whole period I was deliriously happy, but with the perversity of my nature I persevered in my resolution not to see her. Then, as I should have expected, I got no further answers. "She is disgusted," I said to myself, "with what she thinks my timidity in making no more definite advances"; and I resolved to seek her and make her acquaintance and - what? I did not know, nor do I now know, what might have come of it. I know only that I passed days and days trying to meet her, and all in vain; she was invisible as well as inaudible. I haunted the streets where we had met, but she did not come. From my window I watched the garden in front of her house, but she passed neither in nor out. I fell into the deepest dejection, believing that she had gone away , yet took no steps to resolve my doubt by inquiry of my landlady, to whom, indeed, I had taken an unconquerable aversion from her having once spoken of the girl with less of reverence than I thought befitting.

'There came a fateful night. Worn out with emotion, irresolution and despondency, I had retired early and fallen into such sleep as was still possible to me. In the middle of the night something - some malign power bent upon the wrecking of my peace forever - caused me to open my eyes and sit up, wide awake and listening intently for I knew not what. Then I thought I heard a faint tapping on the wall - the mere ghost of the familiar signal. In a few moments it was repeated: one, two, three - no louder than before, but addressing a sense alert and strained to receive it. I was about to reply when the Adversary of Peace again intervened in my affairs with a rascally suggestion of retaliation. She had long and cruelly ignored me; now I would ignore her. Incredible fatuity - may God forgive it! All the rest of the night I lay awake, fortifying my obstinacy with shameless justifications and - listening.

'Late the next morning, as I was leaving the house, I met my landlady, entering.

' "Good morning, Mr. Dampier," she said. "Have you heard the news?"

'I replied in words that I had heard no news; in manner, that I did not care to hear any. The manner escaped her observation.

' "About the sick young lady next door," she babbled on. "What! you did not know? Why, she has been ill for weeks. And now - "

'I almost sprang upon her. "And now," I cried, "now what?'

' "She is dead."

'That is not the whole story. In the middle of the night, as I learned later, the patient, awakening from a long stupor after a week of delirium, had asked - it was her last utterance - that her bed be moved to the opposite side of the room. Those in attendance had thought the request a vagary of her delirium, but had complied. And there the poor passing soul had exerted its failing will to restore a broken connection - a golden thread of sentiment between its innocence and a monstrous baseness owing a blind, brutal allegiance to the Law of Self.

'What reparation could I make? Are there masses that can be said for the repose of souls that are abroad such nights as this - spirits "blown about by the viewless winds" - coming in the storm and darkness with signs and portents, hints of memory and presages of doom?

'This is the third visitation. On the first occasion I was too sceptical to do more than verify by natural methods the character of the incident; on the second, I responded to the signal after it had been several times repeated, but without result. To-night's recurrence completes the 'fatal triad' expounded by Parapelius Necromantius. There is no more to tell.'

When Dampier had finished his story I could think of nothing relevant that I cared to say, and to question him would have been a hideous impertinence. I rose and bade him good night in a way to convey to him a sense of my sympathy, which he silently acknowledged by a pressure of the hand. That night, alone with his sorrow and remorse, he passed into the Unknown.