Once upon a time, among the vast wilderness and meandering rivers, there lay a small village shrouded in mist. Old oak trees grew around it, and the wind often brought words of song from a world long gone. It was a June night, and the sounds of preparations for the Kupala festival could be heard on the banks of the Vistula. Jagoda and Borzymir, two young friends, slipped out of the hut just before dark. The smell of herbs was in the air and the silvery ribbon of the river glittered in the moonlight. People in the village gathered around a large bonfire, laughing and throwing flower garlands to each other. Everyone knew that this night could bring extraordinary things. Berry clutched a bouquet of fern and bumblebee in her hand - according to her grandmother, such a mixture protected against night creatures. Borzymir was eagerly preparing to jump over the fire, wanting to show his courage. However, their real plans were much bolder - they decided to separate from the celebrants and follow the forest path leading deep into the forest. They walked slowly, immersed in silence. As they moved away from the campfire lights, the sounds of the village disappeared and were replaced by the quiet singing of crickets and the rustle of leaves. The darkness between the trees was thick, but the moonlight led them to the bank of the Vistula. There, by an old willow tree, they came upon a ring of scattered stones. In the centre of it lay a moss-covered stone statue - strange, weathered, as if its eyes were closed in slumber. Fresh ferns swirled around it, and golden lights danced in the air, which resembled skylights but moved too gracefully, too deliberately. Berry looked around anxiously. - Did you hear that? - She whispered to Borzymir, who nodded, staring at the figures moving between the trees. They were barely visible - some had long forest hair, others beautiful garlands of flowers, others, similar to shadowy silhouettes, seemed to dance on the surface of the water. - 'They are mermaids,' whispered Borzymir, suddenly aware that they were approaching something unusual. Suddenly, the statue in the centre of the circle shook slightly, and one of its stone eyes opened slowly, flashing with an unearthly radiance. A quiet laugh sounded from the river, and the wind rose around Berry and Borzymir, scattering flower petals and swirling sparks. At the same moment, the darkness lingering behind them moved, as if something - or someone - was approaching faster and faster....