Just arriving at a new school on the first of September seemed completely absurd to Kacper, but when he saw that the school building... was standing on big yellow wheels, he thought it was a joke on the scale of his little brother. - Maybe it's some kind of mobile school? - joked Ola, standing next to him with her nose in her phone. - In a moment it will start driving us around the market and teaching us calligraphy on the corners. Students crowded in front of the entrance. Some were taking pictures of themselves with a huge, rusted sign that read: "IM. SPACE EXPLORERS". Kacper turned to his friend Michael: - 'I'm just waiting for him to make us paint Mars on the carpet while we drive. Michal nodded with the seriousness of an artist, then hissed: - Have you seen the director? Apparently last year he pretended to be a robot and only spoke in zero-one language. Ola snorted with laughter, but at that moment the school doors opened and a man in a cylinder appeared at the top of the metal stairs, with antennae made of ice cream sticks and silver foil stuck to his ears. - Dear students! - he called out with pathos. - Welcome aboard the school of the future! I present to you the latest educational invention: lessons in motion! We're moving in five minutes, so fasten your seatbelts... and get ready for surprises. We'll start with explosive chemical experiments! Everyone looked at each other in disbelief. Kacper felt like he was about to explode - either from curiosity or from laughter. No one yet knew exactly what "explosive experiments" meant, but when the school vehicle suddenly started up and a siren sounded in the corridor, everyone held their breath. Then the headmaster's voice rang out over the loudspeakers: - Attention, attention: we are launching a great Mystery Pack action. Whoever is the first to find the hidden object will receive... And here the signal stopped, and the whole school on wheels turned abruptly towards the dark forest outside the town....