When Marta, a dental student, entered the lab at the university, she didn't expect the day to turn into the adventure of a lifetime. They had just finished working on nanorobots for cleaning teeth when her friend Bartek, a biologist from another department, called. - 'Marta, you've got to see this! - he whispered excitedly into the phone. - 'We're in the Whispering Cave, and inside.... something you won't find in textbooks. An hour later, Marta, Bartek and Kaja, the biotechnology specialist, were already standing at the edge of a glittering tunnel carved into the rock. But this was no ordinary rock - the walls shimmered white like the enamel of the biggest tooth. - Is this a ... tooth? - Kaja asked in a whisper, touching the smooth surface. Bartek nodded his head. - I don't believe it myself. This whole tunnel system is.... kind of like a jaw, huge, fossilised, hidden under the mountains. Suddenly they heard a quiet giggle. Everyone's gazes turned towards the darkness. After a moment, creatures appeared in front of them - slightly shorter than a human, dressed in grey aprons and with heads resembling the tips of toothbrushes. They had entrancing eyes and bizarre, wide smiles. - 'Welcome to Molarion,' the oldest being spoke up. - Do you intend to stay here for any length of time? We have a certain ... hygiene problem that we can't solve ourselves. The team of scientists looked at each other in disbelief. A green light flashed at the end of the corridor, and a long sound flowed into the depths of the jaw - as if someone was sharpening thousands of dental floss. Martha raised her hand with her miniature sonic toothbrush, but then she heard a rustling from the other side of the tunnel - something was approaching faster and faster. Suddenly, the entire underground chamber began to vibrate. Would the scientists help the people of Molarion, or would they meet whatever lurked in the deepest of teeth? The cool air carried an ominous smell from afar.... and everyone froze in anticipation of what would emerge from the darkness.