Ola was seven years old and really enjoyed walking around in her fluffy pink slippers. She lived in a bunkhouse with her parents and her cat Leo. One morning Ola went down to the hallway to put her slippers on her bare feet, but.... The slippers were gone! Instead of them, there was a funny footprint on the floor. It looked like a paw print, but it was neither too small like Leo's paw, nor too big like a human foot. - Leo, did you see my slippers? - asked Ola, but the kitten only purred and stretched lazily. Ola looked more carefully at the footprint. It was shiny, as if someone had left a trail with a paw dipped in glitter. The trail led to the stairs and continued upwards until it disappeared around a corner. - Come on, Leo, let's solve this mystery! - said the girl and moved slowly up the stairs, feeling a thrill of excitement. The slippers had to be somewhere close, but who had taken them? And was it possible that someone else was living in their house? Ola leaned over to check another footprint and.... Just then, a quiet rustling sound came from behind the attic door.