When a mummy disappears from the local history museum while Cass and her friends Max-Ernest and Yo-Yoji are there, they try to solve the case in order to clear their names and, they hope, discover the Secret they have been seeking.
In this mystery story that features interactive puzzles, activities, games, and choose-your-own-adventure scenarios, the reader is led through the steps of writing a book.
Cass finds herself alone and disoriented in a dream-like world, while back at home she is in the hospital in a coma with Max-Ernest desperately searching for a way to awaken her.
Cass's mom is kidnapped by the evil dessert chef, Se?or Hugo, who requests the legendary tuning fork as ransom, leading Cass and Max-Ernest to try finding the magical instrument in time.
Cass and Max-Ernest discover the Museum of Magic, unscramble more coded messages, and solve new mysteries in their attempt to thwart the Terces Society's ambitions of discovering immortality.
Cassandra and Max find a missing magician's notebook and start to investigate the fire which burnt down his house and his mysterious "symphony of smells.".
