Zosia lived in a village under the clouds. Every morning she heard a strange echo from the mountains. It sounded like the breathing of a very large bird. Her friend Cuba was collecting stones by the stream. Together they counted the swallows that circled above the barn. Sometimes Zosia drew dragons on old boards. One day the echo was loud and warm. The echo repeated very quietly: "Dragons... dragons...". Zosia squeezed Kuba's hand tightly. A small blue shell lay on the road. It shimmered like a wet stone after the rain. Kuba whispered: "It's a sign from the Valley of Clouds." Beyond the bridge the old path to the Echo Cave began. Zosia had her dad's torch and a thin string. Inside, water dripped and smelled of smoke. There were round marks on the ground like bowls. At the end of the corridor stood a large egg. It was bigger than a soup pot. The egg vibrated and there was a quiet popping sound. Behind them the heavy stone at the entrance crackled. There was a whiff of heat and smoke from the darkness. Zosia lifted the shell and the egg cracked louder. They heard a soft step just behind them.