Olive flicked her finger across her phone screen for the hundredth time, yawning quietly. She was sitting under an old oak tree at the edge of the park where she had arranged to meet Matthew and Zosia. It was here, on the outskirts of a small town, where civilisation ended and wild greenery and vast, forgotten glades began. It was Friday evening, the holiday was slowly coming to an end and the hot air vibrated with the singing of cicadas. Matthew arrived on his bike, honking his bell loudly. Zosia came on foot, carrying an old camera. - 'Don't tell me you want to take pictures of the same branch again,' laughed Matthew, pointing to the oak branch from which Zosia loved to photograph the wood grain. - 'Today I have a different plan,' replied Zosia with a mysterious smile. - Yesterday, when I was here with the dog, I noticed something strange. There was some kind of metal handle growing under the roots of this tree. For real. Olive looked at it suspiciously, but she and Matthew walked up to the massive trunk. After a while, they actually saw a shiny, bent handle embedded in the ground, between the intertwining roots. - 'I think this is some kind of joke, maybe someone buried something,' Matthew stated, but after a moment he leaned over and pulled the handle. The ground trembled and a quiet creaking sound came from under the oak tree. The roots spread out, revealing a small, rectangular door. All three of them were stunned. - Shall we open it? - whispered Olive, feeling her heart beat faster. Matthew was already halfway in, kneeling at the edge of the opening and peering inside. Zosia slipped her camera behind her belt and leaned over him. There was no darkness behind the door. On the contrary, there was a glow from there, and the air smelled of damp moss and something completely unfamiliar. Moving shadows shone in the depths, and an unsettlingly melodious sound came from the distance, as if music from another world. Olive looked at her friends. Matthew was pale with excitement. Zosia reached out and slowly pressed the door handle. The door swung open wider, and from within it something - someone? - suddenly moved towards them....