one, too, if youperhaps understand what I mean--"

  "It's an odd expression; you used it before, you know," said the authorwearily, yet eagerly listening to every word of the diagnosis, anddeeply touched by the intelligent sympathy which did not at onceindicate the lunatic asylum.

  "Possibly," returned the other, "and an odd affliction, too, you'llallow, yet one not unknown to the nations of antiquity, nor to thosemoderns, perhaps, who recognise the freedom of action under certainpathogenic conditions between this world and another."

  "And you think," asked Pender hastily, "that it is all primarily due tothe _Cannabis_? There is nothing radically amiss with myself--nothingincurable, or--?"

  "Due entirely to the overdose," Dr. Silence replied emphatically, "tothe drug's direct action upon your psychical being. It rendered youultra-sensitive and made you respond to an increased rate of vibration.And, let me tell you, Mr. Pender, that your experiment might have hadresults far more dire. It has brought you into touch with a somewhatsingular class of Invisible, but of one, I think, chiefly human incharacter. You might, however, just as easily have been drawn out ofhuman range altogether, and the results of such a contingency would havebeen exceedingly terrible. Indeed, you would not now be here to tell thetale. I need not alarm you on that score, but mention it as a warningyou will not misunderstand or underrate after what you have beenthrough.

  "You look puzzled. You do not quite gather what I am driving at; and itis not to be expected that you should, for you, I suppose, are thenominal Christian with the nominal Christian's lofty standard of ethics,and his utter ignorance of spiritual possibilities. Beyond a somewhatchildish understanding of 'spiritual wickedness in high places,' youprobably have no conception of what is possible once you break-down theslender gulf that is mercifully fixed between you and that Outer World.But my studies and training have taken me far outside these orthodoxtrips, and I have made experiments that I could scarcely speak to youabout in language that would be intelligible to you."

  He paused a moment to note the breathless interest of Pender's face andmanner. Every word he uttered was calculated; he knew exactly the valueand effect of the emotions he desired to waken in the heart of theafflicted being before him.

  "And from certain knowledge I have gained through various experiences,"he continued calmly, "I can diagnose your case as I said before to beone of psychical invasion."

  "And the nature of this--er--invasion?" stammered the bewildered writerof humorous tales.

  "There is no reason why I should not say at once that I do not yet quiteknow," replied Dr. Silence. "I may first have to make one or twoexperiments--"

  "On me?" gasped Pender, catching his breath.

  "Not exactly," the doctor said, with a grave smile, "but with yourassistance, perhaps. I shall want to test the conditions of thehouse--to ascertain, impossible, the character of the forces, of thisstrange personality that has been haunting you--"

  "At present you have no idea exactly who--what--why--" asked theother in a wild flurry of interest, dread and amazement.

  "I have a very good idea, but no proof rather," returned the doctor."The effects of the drug in altering the scale of time and space, andmerging the senses have nothing primarily to do with the invasion. Theycome to any one who is fool enough to take an experimental dose. It isthe other features of your case that are unusual. You see, you are nowin touch with certain violent emotions, desires, purposes, still activein this house, that were produced in the past by some powerful and evilpersonality that lived here. How long ago, or why they still persist soforcibly, I cannot positively say. But I should judge that they aremerely forces acting automatically with the momentum of their terrificoriginal impetus."

  "Not directed by a living being, a conscious will, you mean?"

  "Possibly not--but none the less dangerous on that account, and moredifficult to deal with. I cannot explain to you in a few minutes thenature of such things, for you have not made the studies that wouldenable you to follow me; but I have reason to believe that on thedissolution at death of a human being, its forces may still persist andcontinue to act in a blind, unconscious fashion. As a rule they speedilydissipate themselves, but in the case of a very powerful personalitythey may last a long time. And, in some cases--of which I incline tothink this is one--these forces may coalesce with certain non-humanentities who thus continue their life indefinitely and increase theirstrength to an unbelievable degree. If the original personality wasevil, the beings attracted to the left-over forces will also be evil. Inthis case, I think there has been an unusual and dreadful aggrandisementof the thoughts and purposes left behind long ago by a woman ofconsummate wickedness and great personal power of character andintellect. Now, do you begin to see what I am driving at a little?"

  Pender stared fixedly at his companion, plain horror showing in hiseyes. But he found nothing to say, and the doctor continued--

  "In your case, predisposed by the action of the drug, you haveexperienced the rush of these forces in undiluted strength. They whollyobliterate in you the sense of humour, fancy, imagination,--all thatmakes for cheerfulness and hope. They seek, though perhaps automaticallyonly, to oust your own thoughts and establish themselves in their place.You are the victim of a psychical invasion. At the same time, you havebecome clairvoyant in the true sense. You are also a clairvoyantvictim."

  Pender mopped his face and sighed. He left his chair and went over tothe fireplace to warm himself.

  "You must think me a quack to talk like this, or a madman," laughed Dr.Silence. "But never mind that. I have come to help you, and I can helpyou if you will do what I tell you. It is very simple: you must leavethis house at once. Oh, never mind the difficulties; we will deal withthose together. I can place another house at your disposal, or I wouldtake the lease here off your hands, and later have it pulled down. Yourcase interests me greatly, and I mean to see you through, so that youhave no anxiety, and can drop back into your old groove of worktomorrow! The drug has provided you, and therefore me, with a shortcutto a very interesting experience. I am grateful to you."

  The author poked the fire vigorously, emotion rising in him like atide. He glanced towards the door nervously.

  "There is no need to alarm your wife or to tell her the details of ourconversation," pursued the other quietly. "Let her know that you willsoon be in possession again of your sense of humour and your health, andexplain that I am lending you another house for six months. Meanwhile Imay have the right to use this house for a night or two for myexperiment. Is that understood between us?"

  "I can only thank you from the bottom of my heart," stammered Pender,unable to find words to express his gratitude.

  Then he hesitated for a moment, searching the doctor's face anxiously.

  "And your experiment with the house?" he said at length.

  "Of the simplest character, my dear Mr. Pender. Although I am myself anartificially trained psychic, and consequently aware of the presence ofdiscarnate entities as a rule, I have so far felt nothing here at all.This makes me sure that the forces acting here are of an unusualdescription. What I propose to do is to make an experiment with a viewof drawing out this evil, coaxing it from its lair, so to speak, inorder that it may _exhaust itself through me_ and become dissipated forever. I have already been inoculated," he added; "I consider myself tobe immune."

  "Heavens above!" gasped the author, collapsing on to a chair.

  "Hell beneath! might be a more appropriate exclamation," the doctorlaughed. "But, seriously, Mr. Pender, this is what I propose to do--withyour permission."

  "Of course, of course," cried the other, "you have my permission and mybest wishes for success. I can see no possible objection, but--"

  "But what?"

  "I pray to Heaven you will not undertake this experiment alone, willyou?"

  "Oh, dear, no; not alone."

  "You will take a companion with good nerves, and reliable in case ofdisaster, won't you?"

  "I shall bring two companions," the doctor sa
id.

  "Ah, that's better. I feel easier. I am sure you must have among youracquaintances men who--"

  "I shall not think of bringing men, Mr. Pender."

  The other looked up sharply.

  "No, or women either; or children."

  "I don't understand. Who will you bring, then?"

  "Animals," explained the doctor, unable to prevent a smile at hiscompanion's expression of surprise--"two animals, a cat and a dog."

  Pender stared as if his eyes would drop out upon the floor, and thenled the way without another word into the adjoining room where his wifewas awaiting them for tea.

  II

  A few days later the humorist and his wife, with minds greatly relieved,moved into a small furnished house placed at their free disposal inanother part of London; and John Silence, intent upon his approachingexperiment, made ready to spend a night in the empty house on the top ofPutney Hill. Only two rooms were prepared for occupation: the study onthe ground floor and the bedroom immediately above it; all other doorswere to be locked, and no servant was to be left in the house. The motorhad orders to call for him at nine o'clock the following morning.

  And, meanwhile, his secretary had instructions to look up the pasthistory and associations of the place, and learn everything he couldconcerning the character of former occupants, recent or remote.

  The animals, by whose sensitiveness he intended to test any unusualconditions in the atmosphere of the building, Dr. Silence selected withcare and judgment. He believed (and had already made curious experimentsto prove it) that animals were more often, and more truly, clairvoyantthan human beings. Many of them, he felt convinced, possessed powers ofperception far superior to that mere keenness of the senses common toall dwellers in the wilds where the senses grow specially alert; theyhad what he termed "animal clairvoyance," and from his experiments withhorses, dogs, cats, and even birds, he had drawn certain deductions,which, however, need not be referred to in detail here.

  Cats, in particular, he believed, were almost continuously conscious ofa larger field of vision, too detailed even for a photographic camera,and quite beyond the reach of normal human organs. He had, further,observed that while dogs were usually terrified in the presence of suchphenomena, cats on the other hand were soothed and satisfied. Theywelcomed manifestations as something belonging peculiarly to their ownregion.

  He selected his animals, therefore, with wisdom so that they mightafford a differing test, each in its own way, and that one should notmerely communicate its own excitement to the other. He took a dog and acat.

  The cat he chose, now full grown, had lived with him since kittenhood, akittenhood of perplexing sweetness and audacious mischief. Wayward itwas and fanciful, ever playing its own mysterious games in the cornersof the room, jumping at invisible nothings, leaping sideways into theair and falling with tiny moccasined feet on to another part of thecarpet, yet with an air of dignified earnestness which showed that theperformance was necessary to its own well-being, and not done merely toimpress a stupid human audience. In the middle of elaborate washing itwould look up, startled, as though to stare at the approach of someInvisible, cocking its little head sideways and putting out a velvet padto inspect cautiously. Then it would get absent-minded, and stare withequal intentness in another direction (just to confuse the onlookers),and suddenly go on furiously washing its body again, but in quite a newplace. Except for a white patch on its breast it was coal black. And itsname was--Smoke.

  "Smoke" described its temperament as well as its appearance. Itsmovements, its individuality, its posing as a little furry mass ofconcealed mysteries, its elfin-like elusiveness, all combined to justifyits name; and a subtle painter might have pictured it as a wisp offloating smoke, the fire below betraying itself at two points only--theglowing eyes.

  All its forces ran to intelligence--secret intelligence, the wordlessincalculable intuition of the Cat. It was, indeed, _the_ cat for thebusiness in hand.

  The selection of the dog was not so simple, for the doctor owned many;but after much deliberation he chose a collie, called Flame from hisyellow coat. True, it was a trifle old, and stiff in the joints, andeven beginning to grow deaf, but, on the other hand, it was a veryparticular friend of Smoke's, and had fathered it from kittenhoodupwards so that a subtle understanding existed between them. It was thisthat turned the balance in its favour, this and its courage. Moreover,though good-tempered, it was a terrible fighter, and its anger whenprovoked by a righteous cause was a fury of fire, and irresistible.

  It had come to him quite young, straight from the shepherd, with the airof the hills yet in its nostrils, and was then little more than skin andbones and teeth. For a collie it was sturdily built, its nose blunterthan most, its yellow hair stiff rather than silky, and it had fulleyes, unlike the slit eyes of its breed. Only its master could touch it,for it ignored strangers, and despised their pattings--when any dared topat it. There was something patriarchal about the old beast. He was inearnest, and went through life with tremendous energy and big things inview, as though he had the reputation of his whole race to uphold. Andto watch him fighting against odds was to understand why he wasterrible.

  In his relations with Smoke he was always absurdly gentle; also he wasfatherly; and at the same time betrayed a certain diffidence or shyness.He recognised that Smoke called for strong yet respectful management.The cat's circuitous methods puzzled him, and his elaborate pretencesperhaps shocked the dog's liking for direct, undisguised action. Yet,while he failed to comprehend these tortuous feline mysteries, he wasnever contemptuous or condescending; and he presided over the safety ofhis furry black friend somewhat as a father, loving, but intuitive,might superintend the vagaries of a wayward and talented child. And, inreturn, Smoke rewarded him with exhibitions of fascinating and audaciousmischief.

  And these brief descriptions of their characters are necessary for theproper understanding of what subsequently took place.

  With Smoke sleeping in the folds of his fur coat, and the collie lyingwatchful on the seat opposite, John Silence went down in his motor afterdinner on the night of November 15th.

  And the fog was so dense that they were obliged to travel at quarterspeed the entire way.

  * * * * *

  It was after ten o'clock when he dismissed the motor and entered thedingy little house with the latchkey provided by Pender. He found thehall gas turned low, and a fire in the study. Books and food had alsobeen placed ready by the servant according to instructions. Coils of fogrushed in after him through the open door and filled the hall andpassage with its cold discomfort.

  The first thing Dr. Silence did was to lock up Smoke in the study with asaucer of milk before the fire, and then make a search of the house withFlame. The dog ran cheerfully behind him all the way while he tried thedoors of the other rooms to make sure they were locked. He nosed aboutinto corners and made little excursions on his own account. His mannerwas expectant. He knew there must be something unusual about theproceeding, because it was contrary to the habits of his whole life notto be asleep at this hour on the mat in front of the fire. He keptlooking up into his master's face, as door after door was tried, with anexpression of intelligent sympathy, but at the same time a certain airof disapproval. Yet everything his master did was good in his eyes, andhe betrayed as little impatience as possible with all this unnecessaryjourneying to and fro. If the doctor was pleased to play this sort ofgame at such an hour of the night, it was surely not for him to object.So he played it, too; and was very busy and earnest about it into thebargain.

  After an uneventful search they came down again to the study, and hereDr. Silence discovered Smoke washing his face calmly in front of thefire. The saucer of milk was licked dry and clean; the preliminaryexamination that cats always make in new surroundings had evidentlybeen satisfactorily concluded. He drew an arm-chair up to the fire,stirred the coals into a blaze, arranged the table and lamp to hissatisfaction for reading, and then prepared surreptitiously t
o watch theanimals. He wished to observe them carefully without their being awareof it.

  Now, in spite of their respective ages, it was the regular custom ofthese two to play together every night before sleep. Smoke always madethe advances, beginning with grave impudence to pat the dog's tail, andFlame played cumbrously, with condescension. It was his duty, ratherthan pleasure; he was glad when it was over, and sometimes he was verydetermined and refused to play at all.

  And this night was one of the occasions on which he was firm.

  The doctor, looking cautiously over the top of his book, watched the catbegin the performance. It started by gazing with an innocent expressionat the dog where he lay with nose on paws and eyes wide open in themiddle of the floor. Then it got up and made as though it meant to walkto the door, going deliberately and very softly. Flame's eyes followedit until it was beyond the range of sight, and then the cat turnedsharply and began patting his tail tentatively with one paw. The tailmoved slightly in reply, and Smoke changed paws and tapped it again. Thedog, however, did not rise to play as was his wont, and the cat fell toparting it briskly with both paws. Flame still lay motionless.

  This puzzled and bored the cat, and it went round and stared hard intoits friend's face to see what was the matter. Perhaps some inarticulatemessage flashed from the dog's eyes into its own little brain, making itunderstand that the programme for the night had better not begin withplay. Perhaps it only realised that its friend was immovable. But,whatever the reason, its usual persistence thenceforward deserted it,and it made no further attempts at persuasion. Smoke yielded at