The Rusalka Forest was a place where the shadows of the trees wove into green corridors and the leaves whispered stories to anyone who dared to listen. It wasn't the first time Zosia, Maks and Igor had wandered here, but this time the forest seemed different, as if every branch was twitching with anticipation. They were in the middle of their holiday, and their favourite game was to track the tracks of wild animals - deer, foxes and sometimes even wild boar. On this day, however, something surprised them. Through the dense ferns they spotted footprints larger than any they had seen before. The paws imprinted in the soft earth had to belong to wolves. But they did not resemble ordinary tracks - each paw seemed to be unnaturally long, and there were scattered particles of strange, shiny gravel around the tracks. "Have you heard that a strange pack of wolves was reportedly seen here recently?" - whispered Igor, looking nervously around. Maks knelt down by the tracks and took a notebook out of his pocket, in which he drew the tracks he had encountered. "These are completely different from the ones we saw before," he muttered. Zosia looked at him with concern. "Maybe it's some new species? Or... Maybe something is happening to our forest?" As they followed the footsteps, the thicket around them grew darker and darker. Suddenly, Maks tripped over something hidden under a layer of leaves. He shrugged off his trousers and pulled out an object - a rusty old compass that pointed north, although the needle trembled, pointing in different directions every now and then. At the same moment, they all heard a protracted howl that seemed to come from all directions simultaneously. Zosia squeezed the compass and looked at her friends. "Do you think this compass .... shows more than just north?" - she asked. Another howl sounded just behind their backs, and the footsteps around them began to glow with a bluish light. The children looked at each other, not knowing whether to go on or run away. And then, from behind a veil of mist, a pair of glowing blinds emerged....