But the real interest of this sitting, to any little demon gifted with a miraculous power of pushing its detective way into the minds of the sitters, would have lain, perhaps, chiefly in the mind of Doctor Levillier.  It has been said that, suddenly struck to the soul by the conviction with which the instinctive Cuckoo pronounced those words, “From Marr,” Doctor Levillier entered into a new world, abandoning old landmarks.  He remained in this new world of the senses certainly, but already he was becoming accustomed to it, clear-headed, keen-sighted, even reasonable in it.  Moved by some strange conviction that he was in the presence of an inexplicable mystery, he no longer tried to explain it in some ordinary fashion.  He abandoned his theory of insanity, or it abandoned him.  In any case, it was dead, buried, whether he would or no.  He recognized a mystery at present beyond his capacity to understand or to explain.  Having got thus far, and having entered, at Julian’s word, into this present circumstance of sitting, table-turning, or rapping, or whatever you may choose to call it, he cleared any ordinary furniture of doctor’s prejudices right out of his mind—­made a clean sweep of them.  That done—­and the doing of it required some strong effort—­his mind was receptive, ready for anything, odd or ordinary, that might come along.  There he sat with his empty room waiting to be filled—­the only reasonable way of waiting for that of which we have no knowledge.  He did not clamour “I won’t,” or “I will.”  He said nothing at all, only waited with the strict desire and intention of recognizing things to be what they truly were, neither dressing them up nor tearing their garments off their backs.  When he put out the light and sat down, what he expected—­so far as he expected anything—­was this, that the addition of darkness would add a cloud to his mind, and endeavour to give various finishing-touches to any spurious excitement created in him, however much against his will, by the enemy’s doings.  In this expectation he was entirely deceived.  The falling of darkness drew a veil from his mind, leaving his mental sight singularly, even preternaturally, clear.  The falling of silence gave an amazing acuteness to his inner sense of hearing.  Certain people are so made that they can, under certain conditions, and at certain moments, hear the workings of their neighbours’ minds, as you and I can hear the whirr of machinery, or the cry of a child in the street.  An ordinary man or woman can only hear a mind when lips, teeth, and tongue utter it with living sounds that set the air in vibration.  These abnormal people hear, in these abnormal moments, the silent murmurs of the mind making no effort at all to utter itself through the usual speech apparatus.  Till this moment the doctor had supposed himself to be an entirely normal man, but he had been sitting only a very short time before he began to become aware of the silent murmurs of these three minds around him.  The darkness