Ola liked to spend her holidays with her grandfather Bruno. Grandpa had a huge garden behind the house, where daisies bloomed and strawberries smelled. Every day, Ola and her cat Sharbus would chase the grass, pick strawberries and watch the butterflies. One morning, when Ola went outside, she noticed something very strange. On the damp ground, just under the cherry tree, she could see small, round footprints. They were very fresh and led towards the wooden shed. "Grey, look! Who could have walked here?" - whispered Ola. The kitten followed her, lifting its tail upwards. The girl crouched down and touched one of the prints with her finger. They were really tiny, and there were tiny grains of grass lying around them. Ola looked around, but apart from her and Sharbus, no one was around. She picked up the magnifying glass she always took on garden adventures. She looked at the footprints again - they were clearly heading for her grandfather's shed. "Maybe it's a hedgehog?" - Ola thought. "Or maybe ... a dwarf?" Greybeard murmured quietly, as if to say, "Let's go check it out!" Ola carefully opened the shed door. There was semi-darkness inside and the smell of wet wood lingered in the air. In the corner something moved quietly. The girl and the kitten stopped as if enchanted. What was hiding in the depths of the shed? Just then they heard a quiet sound, as if someone very, very tiny was tapping on a board....