It must have been then that I noticed the shelf at about one height
with my head. It was really a place for grown-up people to rest their
elbows, but in my distracted state I thought it was probably the
place you were supposed to kneel. Of course, it was on the high
side and not very deep, but I was always good at climbing and
managed to get up all right. Staying up was the trouble. There was
room only for my knees, and nothing you could get a grip on but a
sort of wooden moulding a bit above it. I held on to the moulding
and repeated the words a little louder, and this time something
happened all right. A slide was slammed back; a little light entered
the box, and a man's voice said "Who's there?