Aunt Hedwig, from Canada, has announced a celebration of her birthday at Falkenstein Castle. Time to find a superb chef! Marie de Remoulade appears out of nowhere and - with her wondrous cooking skills - convinces Count of Falkenstein right away that she's the one for the job. Bibi, Tina and Alex are also delighted by the idea - until suddenly Aunt Hedwig's precious necklace disappears. When Marie is also no longer to be found, Bibi and Tina set off on a thrilling search...