Already the sentries were close upon him, when a trap-door opened in the roof, and David jumped down into it. He heard it clang to behind him, and knew he was safe. CHAPTER VII It was neither cold nor wet below the glass roof of the lake, for, as David already knew, when you are completely in the water, from your head to your heels, you never think of saying ‘Oh, how wet it is!’ and it is only when a piece of you is wet, like when you are washing your hands, or a snowball goes down your neck, that you think of wetness. Certainly also it was not cold, because there were so many red-leaf fires burning. Up overhead the moon shone very brightly through what David knew was ice to the ordinary world, but which it was much more correct to call fish-glass, and it made the most lovely lights in it, just as if all the diamond tiaras and emerald and ruby necklaces had been mashed up in the fish-glass. ‘That’s something to know,’ he said to himself. ‘When there’s fish-glass on the lake, I shall make a hole in it and get underneath. What nonsense grown-up people talk! They all say it’s dangerous to get under the ice—fish-glass, but it was the only safe thing to do. I suppose I’d better call on some fish and thank them for rescuing me.’ He began walking towards one of the red fires round which there were a lot of fish collected, but they all looked so very uninterested and solemn (‘just as if they were hearing a sermon in church and not attending,’ thought David), that he decided that he would explore a little first, and turned quickly off in another direction. At once he felt he was not walking any more, for his feet had come off the ground, and he was lying flat a few feet from the floor. This sensation was rather like losing your balance, and he made a sort of wriggle with his feet in order to recover it again. But instead of recovering his footing, he merely darted off at a great speed in a perfectly unexpected direction. ‘Why, it’s a sort of mad flying in the water,’ he said to himself. ‘O-oh, I see, it’s swimming fish-fashion.’ This was a great discovery; he flicked his feet again, and plunged into a great thicket of water-trees that waved and swayed round him. Once more he kicked, but instead of darting forward again, he came to a dead stop, though he couldn’t understand how he had kicked differently from before. Another kick made him spin round, and once again he kicked as he had kicked the first time, and flew out into the open. ‘Take care where you’re going,’ said a thick, bored voice near him, and, turning round very cautiously lest he should fly off again, he saw an old brown trout, not looking at him exactly, but not looking anywhere else. One eye—the only one that David could see, in fact—seemed to be turned towards him rather than towards anything else, but it merely stared vacantly at him, as if it was painted there. ‘I beg your pardon,’ said David, ‘but I don’t seem to go where I want.’