For centuries, the Weles Forest had covered the southern edge of the village of Strzygonka. People rarely ventured into it, because the trees there hummed as if in a foreign language, and the mists rolled in even on hot July afternoons. But for Jagna and Jarek it was a forest like no other - full of adventures and secrets that no village kids knew. One morning, just after a Sunday storm, the siblings found a feather on the doorstep of their cottage. It was unlike any they had ever seen - it glittered in the sunlight with a thousand colours, and when Jagna touched it with her finger, she felt a gentle tingling sensation. Jarek was sure that this feather was not from any ordinary bird. Their grandmother had once mentioned a kingfisher that only appeared when something unusual was happening in the forest. - 'We must follow the trail,' whispered Jagna, tucking the feather behind her belt. They took their rucksacks and slices of bread and butter and set off deep into the Weles Forest, looking for signs among the mossy stones and fallen trees. The sun played among the leaves and the birds sang differently than usual - as if to warn, but also to encourage them to continue on their way. After an hour of walking, they came across pawprints imprinted in the mud, smaller than a fox's, but ending as if in claws. - It must be him! - said Jarek with a beating heart. Suddenly a mist, thick as cream, emerged from behind the thickest oak tree. In the middle of the mist something blue and green lit up, turning slowly in the air. The siblings, holding hands, walked a few more steps. Suddenly, branches rustled just above their heads and they heard a voice unlike any other - sonorous yet serious: - Why have you come to the forest, children of men? Jagna and Jarek looked at each other with wide-open eyes. What awaited them now?