Twelve-year-old Karli doesn’t end up by the sea during the summer holidays, as he’d hoped, but in an abandoned hotel in the Alps, which his parents have decided to renovate. Instead of adventure, he’s faced with scraping off old wallpaper and other tedious odd jobs. However, everything changes the moment Karli accidentally discovers a mysterious floor. The lift transports him back in time, specifically to the pre-war year of 1938. There, Karli befriends a Jewish girl called Hannah and a shoe-shiner named Georg. When Georg is falsely accused of theft, the children decide to find the real culprit. During their investigation, they uncover not only mysterious events but also a great secret hidden behind the walls of the old hotel. This adventure film tells a story of friendship across time, of the courage to face the past, and of the importance of standing up for the truth – whatever the era.