He could not touch any of the parts of these scenes—walls, trees, furniture, and the like—but whether this was because they were truly non-material, or because they always receded at his approach, he was singularly unable to determine. Everything seemed fluid, mutable, and unreal. When he walked, it appeared to be on whatever lower surface the visible scene might have—floor, path, greensward, or such; but upon analysis he always found that the contact was an illusion. There was never any difference in the resisting force met by his feet—and by his hands when he would stoop experimentally—no matter what changes of apparent surface might be involved. He could not describe this foundation or limiting plane on which he walked as anything more definite than a virtually abstract pressure balancing his gravity. Of definite tactile distinctiveness it had none, and supplementing it there seemed to be a kind of restricted levitational force which accomplished transfers of altitude. He could never actually climb stairs, yet would gradually walk up from a lower level to a higher.
Passage from one definite scene to another involved a sort of gliding through a region of shadow or blurred focus where the details of each scene mingled curiously. All the vistas were distinguished by the absence of transient objects, and the indefinite or ambiguous appearance of such semi-transient objects as furniture or details of vegetation. The lighting of every scene was diffuse and perplexing, and of course the scheme of reversed colors—bright red grass, yellow sky with confused black and gray cloud-forms, white tree-trunks, and green brick walls—gave to everything an air of unbelievable grotesquerie. There was an alteration of day and night, which turned out to be a reversal of the normal hours of light and darkness at whatever point on the earth the mirror might be hanging.
This seemingly irrelevant diversity of the scenes puzzled Robert until he realized that they comprised merely such places as had been reflected for long continuous periods in the ancient glass. This also explained the odd absence of transient objects, the generally arbitrary boundaries of vision, and the fact that all exteriors were framed by the outlines of doorways or windows. The glass, it appeared, had power to store up these intangible scenes through long exposure; though it could never absorb anything corporeally, as Robert had been absorbed, except by a very different and particular process.
But—to me at least—the most incredible aspect of the mad phenomenon was the monstrous subversion of our known laws of space involved in the relation of the various illusory scenes to the actual terrestrial regions represented. I have spoken of the glass as storing up the images of these regions, but this is really an inexact definition. In truth, each of the mirror scenes formed a true and quasi-permanent fourth-dimensional projection of the corresponding mundane region; so that whenever Robert moved to a certain part of a certain scene, as he moved into the image of my room when sending his telepathic messages, he was actually in that place itself, on earth—though under spatial conditions which cut off all sensory communication, in either direction, between him and the present tri-dimensional aspect of the place.
Theoretically speaking, a prisoner in the glass could in a few moments go anywhere on our planet—into any place, that is, which had ever been reflected in the mirror's surface. This probably applied even to places where the mirror had not hung long enough to produce a clear illusory scene; the terrestrial region being then represented by a zone of more or less formless shadow. Outside the definite scenes was a seemingly limitless waste of neutral gray shadow about which Robert could never be certain, and into which he never dared stray far lest he become hopelessly lost to the real and mirror worlds alike.
Among the earliest particulars which Robert gave, was the fact that he was not alone in his confinement. Various others, all in antique garb, were in there with him—a corpulent middle-aged gentleman with tied queue and velvet knee-breeches who spoke English fluently though with a marked Scandinavian accent; a rather beautiful small girl with very blonde hair which appeared as glossy dark blue; two apparently mute Negroes whose features contrasted grotesquely with the pallor of their reversed-colored skins; three young men; one young woman; a very small child, almost an infant; and a lean, elderly Dane of extremely distinctive aspect and a kind of half-malign intellectuality of countenance.
This last named individual—Axel Holm, who wore the satin small-clothes, flared-skirted coat, and voluminous full-bottomed periwig of an age more than two centuries in the past—was notable among the little band as being the one responsible for the presence of them all. He it was who, skilled equally in the arts of magic and glass working, had long ago fashioned this strange dimensional prison in which himself, his slaves, and those whom he chose to invite or allure thither were immured unchangingly for as long as the mirror might endure.