Strange things have been happening at King Smile Primary School recently. First, Philip's toothbrush disappeared from his locker. Then the same thing happened to Julka and three other pupils. And when even the form teacher's spare toothbrush disappeared, everyone knew something unusual was going on. That day at the big break, Filip, Julka and their best pal Maks decided to take action. They formed the Smile Keepers Club and came up with a plan. "We need to discover what happened to toothbrushes before someone forgets how important it is to brush your teeth!"- declared Julka, pointing to a big poster in the common room where a happy toothbrush was being held by a happy toothbrush. The first step was to search the school corridors. Philip knelt by the lockers and spotted tiny white marks on the floor. "It's like toothpaste... but who would spill toothpaste in school?"- muttered Maks, raising his eyebrows. The footprints led through the gymnasium to an old sports equipment locker that no one had looked in for months. When they opened the door, they smelled a strange scent of mint. Inside, it was semi-dark and shadows elongated strangely across the walls. "Look!"- whispered Julka, pointing to something in the corner of the room. Something white and fluffy moved suddenly and disappeared behind piles of balls and mattresses.... The children looked at each other with a mixture of excitement and slight fear. Could it be that someone - or something - was hiding in the school locker to steal toothbrushes? Philip gently slipped inside, being careful not to step on the tube of toothpaste lying on the ground. A quiet rustling could be heard in the silence. Julka boldly followed Philip, and Maks stayed right behind them, ready to make an immediate escape if necessary. All three of them moved closer to the corner of the room, trying not to make any noise. Suddenly... Something flashed right in front of their feet and hid behind the big blue mattress. Would they dare to see who they were dealing with? And will they find their toothbrushes? A strange, playful giggle rang out in the darkness....