Leon, Pola, Jasiek and Nela lived on the outskirts of the town of Zarosle. Imagination was their daily companion, especially as the ancient Forest of Shadows stretched in the neighbourhood, which the elders said should be avoided. But who would listen to the adults? Especially when the air smelled like adventure. One Saturday morning, Leon found his grandfather's old compass in his rucksack. The red needle was spinning restlessly, as if it wanted to show something. - Meet me under the old oak tree! - he called out of the window to Pola, and the rest of the friends quickly joined them. With compass in hand, they set off on an expedition deep into the dark green forest. The further they walked, the more the world around them changed colour. The green of the leaves became deeper, the air thicker and the singing of the birds became quieter behind them. Suddenly Jasiek tripped over something hard. They looked more closely and saw that an old iron handle was sticking out from under the moss. With difficulty, they pushed away the leaves and roots until their eyes revealed a massive wooden gate with strange, glittering runes. - Maybe we shouldn't... - Nela began, but the others were already just looking at the door. Leon put his hand on the handle. The gates creaked open, drowning in a bluish glow. When they opened it wide, a mist emerged from behind the threshold, and a shape resembling a giant wolf with feathers instead of fur appeared in it. The wolf looked at them with amber eyes and growled quietly, and the ground trembled beneath their feet. Before they had time to move away, the compass in Leon's hand flashed bright green and there was a swirling light in the air. The door slammed shut with a bang, and the children were left alone, facing the creature that began to slowly move towards them....