I took George by the arm and led him out of the room.
‘George,’ I said to him. ‘We must find out the reason for this at once. I am certain that I felt someone go past me on the stairs. Do those stairs lead to another place, apart from our rooms?’
George thought for a moment.
‘Yes,’ he replied. ‘There is a door at the end of the passageway. It leads up to another room.’
‘Then we must explore it,’ I said. ‘I can’t go back to sleep until I get to the bottom of this. Get the butler to bring a light.’
Soon the butler arrived with a lantern. He looked as nervous as I felt. We began, the three of us. First, we searched the rooms above, where George and I slept. We found nothing unusual. Then we went down to the door at the end of the corridor. I pushed it open. A crazy looking staircase led up into the darkness. Slowly, we climbed the stairs. I went first, with the candle; then George, and last of all, the butler with the lantern. At the top of the stairs, we stepped into a large, low room. Our lights threw strange shadows but there was nothing to find: just a few large boxes, a roll of carpet, and some broken chairs. But in the far corner of the room, we saw an old ladder that led up to a trap door. Just then, I heard the half-groan, half-sigh again. We stood and looked at each other. We all heard the sound.