Gabrysia Zawadzka was a pretty ordinary girl from class 5b, although lately she had been feeling more and more like something stood out. She lived in an old yellow block of flats on Wiśniowa Street, where all the windows overlooked a mysterious park overgrown with vines. It was in this park that something unusual happened. One afternoon, as Gabrysia was returning from school with her textbooks as heavy as a rucksack, she stopped for a moment in the shade of a large chestnut tree. She heard a group of older girls from her block laughing nearby and decided it would be better if they didn't notice her. She closed her eyes, imagining their gaze passing over her as if she were transparent. And suddenly... the world went silent. When she opened her eyes, she saw her hands - or rather, she didn't see them! She was invisible! She pinched herself hard, but still could not see her own legs or arms. It was only after a few minutes, when she breathed deeply and thought how much she wanted to return to normality, that her body slowly became visible. For the next week, Gabrysia tried to understand what had happened. Was it a coincidence? Or does she know how to disappear whenever she wants? Finally, she told her best friend Theodore about everything, who immediately recognised that Gabrysia had a real superpower. After a few failed and a few successful attempts in the park, Teodor came up with a name for their two-person team: the Invisible Gabrysia Club. They were both convinced that if Gabrysia had superpowers, others could have them too. That's why they invited Marysia, a benchmate who always knew the answer to questions that were too difficult and could predict what would happen during class tests. Marysia came to the park on a Saturday and agreed to a 'power test' - she was to guess a random number, which Theodore had written down on a piece of paper and hidden in his shoe. Marysia immediately said: "Seventeen". The next day, Gabrysia suggested they investigate whether anyone else in the school had unusual abilities. They came up with notes to be planted in different areas of the school, asking: "Do you happen to do things that others can't? Let's meet in the park under the chestnut tree at 5pm." Gabrysia, Theodore and Marysia waited at the agreed place for a full hour. As it began to get dark, they decided to go home, but at that exact moment they heard a rustling behind them. A figure slowly emerged from the bushes, its face obscured by a wide hood. Before they could say anything, the figure stretched out its hand in front of it, and the air around it began to shimmer strangely with colours, as if someone had painted it with light. Gabrysia felt something happen that she had never experienced before. Everything around her suddenly went quiet, and the phenomenon continued for a few more seconds. Before they had time to ask their first question, the figure in the hood spoke up in a low, quiet voice: "Can you do it too?"