Gabrys sat bored in his nature lesson, playing with a rustling packet of peppermint gum. His best friend, Lena, whispered: - Did you forget to brush your teeth after breakfast again? You have crumbs on your cheek! Gabrys fluttered his eyelashes and panickedly wiped his face with his sweatshirt sleeve. However, Lena was already busy - she pulled out a small tube of toothpaste and a plastic toothbrush in the shape of a dinosaur from her backpack. - 'I'm going to the bathroom,' she announced and walked sideways out of the classroom, winking at Gabrys to follow her. The school bathroom on the first floor was unusually empty today. Lena was standing by one of the sinks, twirling her toothbrush and humming an imaginary song about clean teeth. Gabrys rushed inside, peering to see if anyone had noticed their escape. Suddenly, something strange caught his attention. In the corner of the bathroom, under the sink, was something he had never seen here before - a small, silver flapper. - 'Hey, did you see that? - What's that? - There's some kind of flap under the sink.... Lena came closer. She pushed back the purple rug and discovered a catch. Gabriel hesitantly pulled on it. To their surprise, the flap opened with a quiet click and revealed a spiral staircase that descended downwards - into the depths of the school, and perhaps even further! They squinted - coloured lights twinkled below and the smell of mint and raspberries wafted through the air. - Shall we go? - asked Lena excitedly. Gabrys only nodded. They went downstairs, and the deeper they got, the more the world changed. Instead of tiles on the walls, they appeared white and shiny, as if made .... - ...made of glaze? I swear, it looks like giant teeth! - exclaimed Lena. At one point, the stairs ended and the children were presented with an amazing sight: a huge city full of walking, talking teeth, dancing toothbrushes, flying dental floss and a dentist who looked like a judge in togs. - Welcome to Toothland! - rang out a booming voice. - Do you know that your habits can affect the fate of our world? Gabriel and Lena looked at each other with their mouths open. Just then, they heard something even more startling - a sinister giggling coming from the dark alley behind the square. All the brushes suddenly stopped dancing and looked in that direction....