I slid Emma’s toy along the curtain, would Emma behind the curtain be curious for what it is? And why the curtain is moving continually and making noises like the toy? She could not think out of it, so she sprang on it directly to have a look. But she always missed it. Pull the curtain open and leave only a layer of thin gauze, Ah-Ha, Emma finally could see it and catch it. Hmm…Why did the familiar sound occur again beside the window? Wait, observe, find the aim, rush to it and catch it! Emma thought this is very interesting, didn’t she? But why she went away at the end?