At the very end of the harbour town, where the waves splashed against the old stone breakwater, stood an abandoned fort. No one knew when exactly it was built, but the children in the area called it the Fort of the Sea Wind. This is where Lena, Krystian and Bartek spent almost every summer afternoon. Most adults considered the place too dangerous, but for the three friends it was the centre of the world, full of nooks and crannies and unexpected treasures. One July day, when the sun was shining so hard that the air above the stones seemed to vibrate, Lena climbed the highest turret of the fort. In its shadow, hidden in a stone alcove, rested something metal. The girl waved to her friends and after a while all three of them were standing around the mysterious object. It was an old brass compass, covered in cobwebs and dust, and the needle twitched constantly, as if it could not point north. "Look!" - exclaimed Bartek. "There's some writing engraved on the underside!". The boy rubbed the compass with his T-shirt. A clear drawing of lightning and the words appeared on the metal: "Follow the light and you will find what you are looking for". Krystian scratched his head. "Maybe it's just a toy?" - he muttered. But as Lena gently rotated the compass around its axis, the needle stopped abruptly, not in the north, but towards the dense, mysterious forest growing just outside the fort. It was a forbidding area, rumoured to be full of sinkholes and strange animals about which all sorts of stories circulated. The friends looked at each other, and uncertainty mixed with excitement hung in the air. "What if the compass is leading us to something unusual?" - Lena asked, her eyes shining with excitement. They decided to follow the indication of the needle. Each of them felt their hearts beating faster as they crossed the scrubland. The shadows in the woods were longer and the sounds muffled, as if the air was becoming thicker. After a few minutes of walking, they came across a fallen log that looked just like a bridge leading deep into a tangle of branches. Suddenly, the compass began to glow with a soft blue light and the needle whirled frantically. Lena swallowed her saliva. "Are you seeing the same thing as me?" - she whispered. Before them, among the ferns, emerged the outline of something that did not resemble an ordinary tree at all. It resembled rather... a huge gate, entwined with ivy and covered in old runes. The rustle of leaves caught their attention - someone or something was approaching from behind....