Nancy, George, and Bess head to Paris for a few weeks, and Carson was nice enough to rent them a small apartment that sits on top of a marionette theater and museum. Marie, the owner, welcomes them, shows them to their apartment, and then takes them out for lunch. She explains that the theater was in her family for years but that financial problems are forcing her to seriously consider selling the property to someone else. William, her lawyer, thinks she should sell to his business partner, Cristophe. Cristophe wants to keep it open but thinks he can do a better job of running it.
We meet William when he comes for a visit and recommends, once again, that she sell. Marie also has a distant cousin named Claude who keeps hanging around. He thinks that the building should remain in the family and is ticked off that he didn't get any money from their grandmother's estate. Claude is suspicious because he keeps hanging around and getting in the way. Marie recently fired Quentin, her best worker, because she couldn't afford to pay him.
The girls offer to do whatever they can to help, which leads to them agreeing to help her put on a show at some upcoming festival. Bess turns out to be so good with one of the marionettes that Marie even asks her to play one of the characters during the show. On their second day, someone sets the studio on fire. The police rule it as arson and actually suspect Marie did it to escape the theater with the insurance money, though she swears she would never do that.
While out at a cafe, Marie runs into Patrice, an old friend of hers from school. Patrice came back to town just to see the show and her former friend. Marie tells all the women in her life that her grandmother Juliette left behind notes about a family treasure that she hopes to find. No one believes her, but Nancy agrees to check things out and reads over a journal the woman kept that seems to include clues that really do lead to some fortune. It begins looking like it might have something to do with the marionettes, which date back generations in the family.
That makes more sense after someone breaks in and steals two of the dolls. They come back on another day and find that someone stole the doll Bess kept in her room and that the person is still there. He/she shoves Bess down hard enough to almost hurt her. Though they give chase, the person literally jumps from rooftop to rooftop to get away. They later find the mutilated doll.
Marie tells Nancy about this book she once had on famous marionette operators and how she misplaced it. She tracks a copy down from a book vendor in the hopes that it might reveal more secrets about the family treasure. Nancy finds other evidence like a matchbook from an exclusive club that both William and Christophe belong to, but that means nothing because anyone can walk through the front doors of the club and pick one up.
More investigation leads to her finding a wooden tray with different spaces for inlaying things on top. Nancy finds everything needed to open it but only uncovers a piece of paper with some characters written on it, which George recognizes as the names of characters from The Hunchback of Notre Dame. Nancy also catches Claude and Christophe deep in conversation and records them. Marie translates it and learns that the two are working together to find her family's secret treasure.
Nancy keeps stumbling onto random things like a photo of Juliette in an antique shop that shows her standing in front of something that exactly matches leather panels made for the marionette show. Someone knocks her out and locks her inside a wooden box, but because she's oh so smart, she somehow manages to get out and escape.
We then make it to the fancy festival. Nancy sees someone sneaking around backstage and gives chase. Though she almost loses the person, she catches up and finds Claude. Claude goes crazy, which leads to the cops arresting him. He claims that he did do a few things to Marie because she cheated him out of the family fortune and that he attacked Nancy but that he didn't do everything.
Nancy sends Patrice a note that she says for her to give to Marie but is actually part of a plan to set Patrice up. Patrice shows up, thinking that Nancy knows the truth of the fortune, and instead finds them all waiting for her. She confesses that while doing research for a book she wanted to write, she found out about the treasure. She also learned that Marie's grandfather killed her own grandfather in a duel and found letters about the treasure. Patrice was the one who started the fire and did some of the other stuff.
They show her the paper they found, but Patrice refuses to believe that Juliette would go to such great lengths just to hide a piece of paper. After the cops come and take her away, Nancy puts all the pieces together and takes everyone to the leather panel she spotted before. It's actually thicker than all the other panels. They open it up and find the handwritten manuscript for the first draft of The Hunchback of Notre Dame inside. It turns out there was some family connection between Victor Hugo and Marie's family, which led to him gifting the draft. She can sell it for more than enough to save the family museum and theater.
*Bess used all her frequent flyer points to get them all tickets to Paris for just $200 each. I totally want to be Bess's new best friend.
*I'm starting to think that every time Bess leaves River Heights, she discovers some new hidden talent. There was the whole pastry chef thing in that one book and now she's secretly a master puppeteer.
*Quentin, her old assistant, is a major suspect because she fired him and he works in a restaurant near the secret club. He explains that he worked there, even while working for her, because he needed the money. None of them believe him because why in the world would someone need to work two jobs? I'm totally rolling my eyes right now.
*George is such a fan of Victor Hugo, she says he's her favorite author, that she can literally recognize his handwriting on the page. Yeah, I like a lot of writers but have no clue what their handwriting looks like.
*After reading the book and seeing the cover so many times, I cannot get the N*SYNC song out of my head!