On the outskirts of Old Town, where the legend of the underground passages had resonated for years, seventeen-year-old Adam was stuck in the attic at night, browsing the internet for a project idea for biology. Everyone had already chosen topics about the heart, the brain, even mitochondria, and to him fell.... the digestive system. By chance, clicking on a link recommended by a friend, he ended up on the 'Jamoustarni' forum. A post entitled "Shadows of the Vacuum" caught his eye: "Someone is sabotaging toothpaste in the Old Town. Who dares to find out where more tubes are disappearing to?". Adam felt a shudder. He still remembered the strange dark silhouettes in the toothpaste aisle at the drugstore he had flashed a week earlier - then he had ignored the incident. Now, spurred on by the mysterious post and the atmosphere of the night town, he quickly packed up his toothbrush, torch and notebook of notes. He met up with Maja, his friend who has always been fascinated by urban exploring. They agreed that they would start their search at the former community centre - the place where, according to the post, Shadows of the Vanity had last been seen. There, under the old stage, they found a dishevelled ventilation grille, through which a sweet, minty smell was oozing. She pushed it open with a clatter. Inside stretched a narrow corridor, filled with shelves full of .... empty toothpaste packets and unfinished toothbrushes. The echo of footsteps was lost in the labyrinth of the underworld. At the end of the corridor, there was a light and silhouettes moving in the dense shadow. Adam and Maja froze when a quiet, almost demonic whisper came from within the darkness: - We knew you would come eventually. You have something that belongs to us.... Adam squeezed the brush in his pocket. The shadows slowly began to approach and the minty smell became more and more intense....