An exciting time travel adventure for children aged 10 and up – full of puzzles and mysterious inventions. Holly must dive deep into her family's past to uncover the secret. Eagerly anticipating her reunion with Aunt Claire, Holly stands before the Memora Castle mansion. But Aunt Claire has seemingly vanished without a trace. Even the unfriendly housekeeper Kendrik has no explanation for her disappearance. Holly quickly realizes that something is not right in the old house. Is the cuckoo from the grandfather clock actually alive? And where does the painted door on the balustrade lead? Together with her cousin Ilana and her stepbrother Janko, Holly sets out to find Aunt Claire and solve the mysterious puzzles – but to do so, the three must leave their own time behind and travel far into the past.