The sun was already setting when Julka pulled Frank by the sleeve. "Come on, let's see if the ferns are blooming in the forest already!" - she whispered. It was Kupala Night, the shortest night of the year, and Grandma had been repeating tales of magical flowers, wolf fires and spirits celebrating an indulgence among the trees since morning. Franek would have been happiest to stay by the fire, where the elders sang songs and baked bread on a stick, but curiosity won out. He and his sister approached the edge of the forest. The shadow grew thicker and thicker and the smell of herbs lingered in the air. In the distance, they could hear an owl hooting and a breeze rustling among the leaves. Julka held in her hand a garland of wild flowers that she had braided herself. Franek took a thin torch from his pocket - it was to be their secret weapon on the expedition. They went deeper, avoiding the spurs and nettles. After a while, they saw something unusual: a soft golden light shone among the ferns, as if someone had spilled honey on the leaves. But it was not a fire or a lamp. As they came closer, the light began to move, as if dancing just above the ground. Julka was already about to stretch out her hand when a laugh sounded from the other side - quiet and resonant, and then another, louder and louder. Small figures emerged from the darkness - they had long, greenish hair, green outfits interspersed with flowers and were smiling broadly at the children. Julka and Franek froze in awe. They had never seen such creatures before. The bravest of them came closer and bowed low: "Hello, people. Why have you come to our forest on the night of the Fern Flower?" - she asked in a voice reminiscent of birdsong. Julka looked at Frank and then at the green-haired figure. She didn't know whether to run away or answer the question. Silence hung in the air, and the fern leaves suddenly trembled, as if something large was approaching the clearing....