A group of teenagers discover a strange passage to an invisible city under the school bathroom. They will face challenges that will test their hygiene habits.
You wouldn't believe what can happen on an ordinary Friday after school, especially if you are part of a team of overly curious teenagers. Bartek tended to keep to himself, Zosia tried everything and Lena had a knack for finding things that others overlooked. Their school, built in the early 20th century, had long since ceased to be a place full of surprises - or so they thought.
They had just finished checking that the broken hand dryer in the school bathrooms had finally been repaired when Bartek suddenly tripped over a tile, which made a deafening, hollow sound. Feeling an impulse, Lena knelt down and tapped the floor. The tile lifted slightly, and from beneath it they pulled out an old piece of paper - strangely yellowed, written in handwriting:
"If you're reading this note, get your toothbrush ready. The door will only be opened by the daredevil with the cleanest smile."
They were silent for a moment, then Zosia snorted with laughter. "It's probably some old school game. Besides, who takes a toothbrush to school?" But before she could finish, Lena stuck her hand into the protrusion under the tile and suddenly a whole section of the floor gave way beneath them. They screamed, falling into the darkness.
They landed gently on something that resembled a large jumping cushion. As their eyes adjusted to the semi-darkness, they saw before them a long, narrow tunnel covered with shapes resembling incisors and molars. The entire walls were made of something resembling enamel, and hanging from the ceiling were threads resembling.... dental floss?
"I think... I think we've stepped into some kind of big mouth?" - howled Bartek, looking around uncertainly.
Suddenly they heard a soft rustle. A shadow emerged from the depths of the tunnel - a figure in a white coat with a mirror on his forehead and a powerful brush in his hand. His voice echoed along the glassy white walls:
"Only those who know how to take care of their teeth can move on. Are you ready for a test of hygiene?"
Bartek, Zosia and Lena looked at each other. They were sure of one thing: this would be no ordinary task. A light flashed in the tunnel and a mysterious figure lifted a brush. A quiet crunch sounded behind them, as if a door was closing. Several passageways appeared in front of them - each marked with a different symbol: dental floss, toothpaste and a clock measuring two minutes.
In a moment, they were to choose which way to go and begin their trial. But were they all prepared enough to meet the demands of the city of underground teeth?