When famed opera singer Violetta von Cacklefur arrives in Gloomeria to perform at the Royal Mousetropolitan Theater, she encounters a chilling surprise—a mischievous phantom with a century-old grudge. It’s up to Creepella von Cacklefur and her fearless friend Geronimo Stilton to navigate the theater’s shadowy corridors and solve the mystery before the final curtain falls and the show spirals into chaos. A perfect blend of ghostly thrills, humor, and detective flair for young readers.