The town of Aurora had plenty of secrets, but most people didn't expect to find them under the old stone bridge on the edge of Azure Park. The bridge was a meeting place for local youths, who would paint graffiti on it or arrange stones underneath it in strange patterns. However, for the three friends - Cuba, Nina and Matthew - it was primarily a point of excursions where they tried to discover something that no one had seen before. One afternoon, as the sun was already setting and a light mist drifted under the bridge, Nina noticed something that had escaped the attention of even the most curious young explorers. In the shadow of one of the supports, just off the ground, a hazy shape was reflecting light in a way that could not be considered ordinary. At first they thought it was an optical illusion. But when Matthew moved his hand over the old brick - the brick trembled and a grid of silver lines flashed through the air. - Can you see it? - whispered Nina, holding her breath. Cuba, who was sceptical about all the tales of the city's strangeness, crouched down right next to her and looked at the shiny lines. When he touched them with his fingers, the lines spread out to the sides, forming a small but distinct doorway. There were no bricks or earth behind them, just something that resembled a thick, swirling mist in which tiny sparks of light danced. For a moment everyone was silent, unsure whether they should go inside. Matthew was the first to gather his courage. He moved his face to the opening and tried to look inside, but the mist obscured his view. Suddenly they heard a sound, as if a quiet whisper had emerged from within. - 'This place... attracts us,' Nina said in a trembling voice. - I can feel it. Cuba looked at his friends. - Are we going in or not? They didn't have time to make up their minds as the door began to slowly close. Matthew dashed forward, crossing the threshold, and Nina and Kuba instinctively moved behind him. The fog engulfed them completely, and when they regained their orientation, instead of under the bridge, they were standing on the shore of a mirror-black lake. There were pulsating lights floating around, and on the opposite side stood a cloaked figure who turned to them with an outstretched hand