Zosia was fourteen years old and knew the forest better than the pavement in front of the house. Her grandfather, a forester, had taught her to read the tracks, to listen to the wind and the silence. That morning he handed her a receiver that squeaked in short, nervous tones. - It is Silver, the wolf with the transmitter, who has been disappearing from the tracking map since yesterday. The signal is jumping, as if something is suppressing it near the Black Pines. Zosia put on her rucksack, took her binoculars and an old, scratched compass from her grandfather. Next to her walked Kuba, an upstairs neighbour who knew the paths in his own way. - 'If we lose the wolf, we'll lose the holiday too,' he muttered, feigning courage. A raven floated above the treetops, as black as the December glaze on the road. It circled above them, squawking briefly, as if keeping an eye on distance and direction. The nearer they got to the Black Pines, the receiver beeped more often and suddenly became quiet. The ground softened underfoot and the smell of resin lurked. A brown hair, longer than a deer's, lay on the pale green moss. Zosia bent down, touched it and felt a cool, metallic aftertaste. - 'The wolf was here, but someone is already following him,' she whispered to Kuba. Between the trunks they saw a thin net, stretched freshly, interspersed with forest needles. On the wire hung two raven feathers and a yellow collar band. The receiver whinnied a continuous sound, as if it had panicked for no human reason. A short, broken whine came from the distance, rocking the air between the pines. Cuba took a step back, but Zosia took two, straight into the shadows. - See, there's a mark on the bark, a circle with three dashes. The crow perched above them and fell silent, as if waiting for the enemy to move. The needles rustled as two yellow, watchful blinds slid out of the bushes. Something large stood between them and the path, and the receiver suddenly fell silent. A hiss came from the shadows, like cracking ice, and the air grew thick. A paw print formed on the wet sand, huge and fresh, trembling as if it were alive. At the same moment a torch flashed on the other side of the grid. Someone whistled a short tune and a raven swooped down, cutting the air with its wings. Zosia lifted her head and saw that the yellow band had burnished numbers on it. Her name was there, in thick letters that no one should leave here.