Lena was a curious seven-year-old girl. One rainy afternoon she was playing in her room when she heard a quiet buzzing coming from behind a large wardrobe. Startled, she pushed her toys away and looked at the wall. To her surprise, she noticed a tiny blue door there that she had never seen before. The door was decorated with shiny stars and a small, round handle. Lena felt her heart speed up and her hands shake slightly with emotion. - Can I open them? - she whispered to herself, looking around to make sure no one was watching. Without hesitation, Lena turned the handle. Just outside the door, a light flashed and Lena felt a gentle blast of warm air. She peeked through the opening and was blown away by the sensation. Beyond the door stretched a wonderland, full of glowing, flying balls and colourful, bouncing mushrooms. The tall, glittering trees had leaves as if made of glitter, and the path beneath Lena's feet shimmered in all the colours of the rainbow. In the middle of it, a little pink light was waiting for her, waving its wing at her. - Come on, Lena! - she called out in a thin voice. - You must see something very important! Lena, feeling as brave as ever, took the first step out of the door.... and then she felt a soft carpet of petals under her feet, and the laughter of other strange creatures in the distance. Suddenly, right in front of her, a huge silver shadow appeared on the path. The lights went silent and the mushrooms stopped popping. Lena held her breath as she watched the shadow begin to move and come straight towards her....