The July evening was hot, and the air in old Sosnowiec was sticky to the skin like transparent film. Diana, reading a thick volume of fantasy, was sitting on a jittery bicycle that had long been begging for new brakes. Next to her, Emil, her best mate since primary school, was dragging his camera bag behind him. After all, today they were going to discover something to add meaning to their holiday afternoons. - 'What if we don't find anything interesting? - Emil asked, wrinkling his eyebrows. His passion for photography and history made him a born tracker, but sometimes doubts took over. - 'Then we'll go home and watch the TV series,' chuckled Diana lightly. - 'But first we'll give it a try. They stopped by the fence of the old villa. The façade was falling off in patches, and the shadow of a colonnade was indistinct behind an overgrown gate. The villa was well-known to the locals - apparently, before the war, an eccentric scientist had lived here and disappeared for weeks at a time. Today, the property belonged to the city and was awaiting demolition. - Can you see it? - whispered Emil, pointing to a door with an etched sign resembling a stylised letter A. - 'The Arcadion,' said Diana. - 'That's what the villa was called, remember? They opened the gate - surprisingly easily, as if it had been left for them. They pushed their bikes through the overgrown garden and went inside. The smell of dust and old books filled the interior. Cracks swirled along the walls, revealing traces of once ornate frescoes. The most interesting part, however, was the hall - a two-storey hall with a mirrored door in the middle. They reflected gnarled figures peering in, and a faint beam of light fell through the dirty glass. Emil set up his camera and Diana began to examine the door frame. - 'What's that indentation? - Emil became interested. There was a circular hole at the very edge, as if there was a piece missing. Diana pulled a coin out of her pocket that she had found outside the entrance to the garden - an old, ornate one with the number '8' on the reverse. She tried applying it to the hole. At that moment, the air trembled and light came alive in the glass doorway - an unfamiliar space reflected in the mirror: vast, full of bridges suspended in the air and monumental buildings of a different material than they knew. A quiet murmur came from behind the door, and the floor beneath their feet trembled. The hue of the light changed, taking on a deep golden hue. Suddenly, the door swung open, and a pair of eyes the colour of steel sky emerged from the other side....