Victor has always been curious, but it was curiosity that got him into trouble that day. When the school nurse asked him and his friends-Lena and Kacper-to bring the old cardboard boxes to the basement, they were not expecting anything out of the ordinary. The basement of the school was a place no one went to willingly: cold, dusty and full of cobwebs. But Victor noticed something that immediately caught his attention. Behind the oldest bookcase, between the old desks, was a huge, round mirror that in no way matched its surroundings. Set in a metal frame engraved with strange symbols, it looked like something that would belong in an eccentric art collection rather than in a school basement. Lena, who always had a ready answer for everything, squinted: - 'It's definitely some old props from a play. Let's leave it at that. But Kacper had already come closer and reached out his hand to the surface of the mirror. Instead of cold glass, he felt warm, as if he were touching the surface of water on a summer day. Victor and Lena looked at each other in disbelief. - Don't do it-Lena said when Kacper put his hand on the mirror. Suddenly the panel trembled and the light began to pulsate to the rhythm of their rapid breaths. On the other side of the mirror, the outlines of a corridor, which definitely did not belong to their school, began to tinkle. Victor sensed that this was no ordinary mirror. Something told him to take a step forward. Kacper was already almost entirely absorbed by its surface, and Lena-despite her uncertainty-decided to follow her friends. On the other side, it wasn't dark at all. On the contrary-glittering vines hung from the ceiling, and the smell of citrus and smoke filled the air. They stood in the middle of a wide corridor carved into the rock, at the end of which a blue light twinkled. Each of them felt a thrill of excitement and anxiety. Suddenly there was a rustle. A cloaked figure emerged from the darkness of the corridor, torch in hand. Her face was lost in shadow, but her voice was soft and surprisingly familiar. - We have been waiting for you. Victor looked at his friends. Anything could happen now-and they had just taken their first step into a world they had never even dreamed of.