“Then, just as I was making an end, a low, mocking whistle grew in the room.  A cold, nervous pricking went up my spine, and ’round my forehead from the back.  The hideous sound filled all the room with an extraordinary, grotesque parody of human whistling, too gigantic to be human—­as if something gargantuan and monstrous made the sounds softly.  As I stood there a last moment, pressing down the final seal, I had no doubt but that I had come across one of those rare and horrible cases of the Inanimate reproducing the functions of the Animate, I made a grab for my lamp, and went quickly to the door, looking over my shoulder, and listening for the thing that I expected.  It came, just as I got my hand upon the handle—­a squeal of incredible, malevolent anger, piercing through the low hooning of the whistling.  I dashed out, slamming the door and locking it.  I leant a little against the opposite wall of the corridor, feeling rather funny; for it had been a narrow squeak....  ’Theyr be noe sayfetie to be gained bye gayrds of holieness when the monyster hath pow’r to speak throe woode and stoene.’  So runs the passage in the Sigsand MS., and I proved it in that ‘Nodding Door’ business.  There is no protection against this particular form of monster, except, possibly, for a fractional period of time; for it can reproduce itself in, or take to its purpose, the very protective material which you may use, and has the power to ’forme wythine the pentycle’; though not immediately.  There is, of course, the possibility of the Unknown Last Line of the Saaamaaa Ritual being uttered; but it is too uncertain to count upon, and the danger is too hideous; and even then it has no power to protect for more than ’maybee fyve beats of the harte,’ as the Sigsand has it.

“Inside of the room, there was now a constant, meditative, hooning whistling; but presently this ceased, and the silence seemed worse; for there is such a sense of hidden mischief in a silence.

“After a little, I sealed the door with crossed hairs, and then cleared off down the great passage, and so to bed.

“For a long time I lay awake; but managed eventually to get some sleep.  Yet, about two o’clock I was waked by the hooning whistling of the room coming to me, even through the closed doors.  The sound was tremendous, and seemed to beat through the whole house with a presiding sense of terror.  As if (I remember thinking) some monstrous giant had been holding mad carnival with itself at the end of that great passage.

“I got up and sat on the edge of the bed, wondering whether to go along and have a look at the seal; and suddenly there came a thump on my door, and Tassoc walked in, with his dressing gown over his pajamas.

“‘I thought it would have waked you, so I came along to have a talk,’ he said. ‘I can’t sleep.  Beautiful!  Isn’t it!’

“‘Extraordinary!’ I said, and tossed him my case.

“He lit a cigarette, and we sat and talked for about an hour; and all the time that noise went on, down at the end of the big corridor.