At the end of a quiet street lived Lena. She was seven years old and had red hair. She loved cardboard kites and tall trees. One morning the wind spoke like someone familiar. Lena heard her name in the rustle of the leaves. Behind the fence a white dog, Petal, was asleep. In his kennel hung a small silver whistle. - Lena, listen - it hummed over her ear. The girl stood up and the kite vibrated in her hand. Suddenly the thread moved on its own, like a living thread. The kite soared without wind, light as a feather. Lena felt that she was controlling it with just a thought. The petal raised its ears and swished its tail. - Do you want to try it further? - asked the whisper of the wind. Lena nodded and pointed to the lighthouse on the corner. The kite turned politely, like a bird in flight. Then three strange clouds appeared in the sky. They were shaped like keys and glided straight over the school. One cloud flashed as if it was opening an invisible door....