I felt fairly sure that no one saw me until it began to grow dark and I carried out the lamp.

Even then, it was Scharnhoff who struck the match and lit it, so that I was in shadow all the time-- probably unrecognizable.
It had been fairly easy to keep awake until then, but as the room grew darker and darker, and nothing happened, the yearning to fall asleep became actual agony.

It was a rather large, square room, crowded up with a jumble of antiquities.

The only real furniture was the window-seat on which I knelt, and an oblong table; but even the table was laid on its side to make room for a battered Roman bust standing on the floor between its legs.
I had left the door of the room wide open, in order to be able to hear anything that might happen in the house; but the only sound came from a couple of rats that gnawed and rustled interminably among the rubbish in the corner.
It must have been nearly eight o'clock, and I believe I had actually dozed off at last, kneeling in the window, when all at once it seemed to me that the rats were making a different, and greater noise than I ever heard rats make.

It was pitch-black dark.