Beware, the Usurpers!

Have you ever seen monsters stalking the streets? Only if you're drunk, you say?—Don't laugh— your best friend could be one of them!...
I stopped the black Jaguar beside the crumbling stone balustrade and swung my legs out. The drive was deep in rotted leaves and long-uncleared trash. Above me the ancient castle looked out across the groves of oak and elm and chestnut to the silent moors, like the veritable ghost of Old England itself: aloof, brooding, noble, withdrawn from this hectic modern age into its memories. Blind blank holes of windows stared over my head as I walked up the drive where in a more regal century the carriages of dukes and knights and princes of the blood must have rolled, the big horses of neighboring squires must have pawed impatiently before many a hunt, and lovers in satin and velvet and cascading lace must have strolled and dallied a thousand thousand times.
As I was hauling open the heavy iron-banded door, my foot trod upon something that squashed unpleasantly. I bent down, and in the sick yellow moonlight saw a newly-dead rook, its eyes already pecked out. I shivered, uncontrollably. Then I went in and pulled the door shut.
My electric torch stabbing the darkness before me, I crossed the empty hall and mounted the broad curving stairs. At the top I turned and glanced downward; the great hall was patterned with moonlight, and although there was no furniture of any sort, the whole vast place seemed to crawl and pulse with shapes of menace, of dead-yet-living evil. I shook myself angrily. My nerves were rotten, my mind was bursting with fear. That was the whole trouble—fear, fear and nerves. The only thing to do was act quickly.
I strode down the dank passageway, opened the third door on the left, went into the room and shut the door behind me.
Here the old stone walls were ashine with lights, the air was less musty and far less creepy. Six people were here, standing about or sitting on straight-backed chairs. They all turned to look at me. Nobody spoke. I nodded to each in turn.